The first generation Firebirds had a what is called "Coke bottle" styling, and unlike its corporate cousin Chevrolet Camaro, the Firebird's bumpers were integrated into the design of the front end. Its rear "slit" taillights were inspired by the Pontiac GTO. Both a two-door hardtop and a convertible were offered through the 1969 model year. At first it was said that the car was a "consolation prize" for Pontiac, who had initially wanted to produce a two-seat sports car of its own design based on the original Banshee concept car.

However, Chevrolet feared such a vehicle would directly compete with its Corvette and convinced GM brass to only give Pontiac a piece of the pony car market by having them share the F-body platform with Chevrolet. In fact, that market might also have been closed off to Pontiac, but the knowledge that Mercury would soon produce the Cougar sealed the deal.

When introduced, the 1967 base model Firebird came equipped with the OHC inline-6 and a single-barrel carburetor rated at 165 HP. The next model, the Sprint, had a four-barrel carburetor equipped SOHC Six, developing 215 HP. Most buyers opted for one of the upscale engines: the 326 CID V8 with a two-barrel carburetor producing 250 HP, or the 326 HO with a four-barrel carburetor producing 285 HP. Further up the scale was the 400 CID V8 borrowed from the GTO with 325 HP. At the top of the heap was a 400 Ram Air rated at 335 HP.

The styling difference from the 1967 to the 1968 model was the addition of Federally mandated side marker lights: for the front of the car, the lower valence-mounted turn signals were made larger and extended to wrap around the front edges of the car, and on the rear, the Pontiac (V-shaped) Arrowhead logo was added to each side. The front door vent-windows were replaced with a single pane of glass. The The 230 CID SOHC engines were replaced by 250 CID version, the single barrel developing 175 HP and the Quadrajet version making 215 HP. 326 CID V8 engine was also replaced by a 350 V8 rated at 265 HP and an HO version rated at 320 HP.The 400 CID offerings were 330 and in the 400 HO, 335 HP.

A "Ram Air" option for the 400 CID was again available in 1968, providing functional hood scoops, higher flow heads with stronger valve springs, and a different camshaft. Power for the Ram Air package was the same as the conventional 400 HO, but the engine peaked at a higher RPM. At mid-year, a Ram Air II version rated at 340 HP would be offered.

The 1969 model received a major facelift with a new front end design, but unlike its big brother the GTO, it did not have the Endura bumper. The instrument panel and steering wheel were revised. The ignition switch was moved from the dashboard to the steering column with the introduction of GM's new locking ignition switch/steering wheel.

Also in 1969, a $725 optional handling package and including a rear deck spoiler was made available called the "Trans Am Performance and Appearance Package. There was an additional Ram Air IV option for the 400 CID engine during that year, complementing the 400 HO, also known as the Ram Air III; these generated 345 and 335 HP respectively. The 350 "H.O." engine was revised again with a different cam and cylinder heads resulting in 330 HP. The standard 400 V8 was rated at 330 HP. The base 350 remained at 265 HP, and the 350 HO was still 325. The OHC I6 also remained at the previous year's ratings of 175 and 215 HP respectively. During 1969 a special 303 cu in (5.0 L) engine was designed for SCCA road racing applications that was never available in production cars.

Due to engineering problems that delayed the introduction of the all-new 1970 Firebird beyond the usual fall debut, Pontiac continued production of 1969 model Firebirds into the early months of the 1970 model year. By late spring of 1969, Pontiac had deleted all model-year references on Firebird literature and promotional materials, anticipating the extended production run of the then-current 1969 models.

Styled by studio head, Bill Porter, the all new design featured a split oval grille opening surrounded by Endura urethane rubber bumper, two headlamps, a long flat hood on the base and Esprit models, a twin-scooped variant on the Formula 400, and a "shaker" hood on the Trans Am. No convertibles were produced during this styling generation that would last through 1981. This look would epitomize F-body styling for the longest period during the Firebird's lifetime. The new design was initially characterized with a large C-pillar, until 1975 when the rear window was enlarged. There were two Ram Air 400 CID V8s for 1970: the 335 HP Ram Air III and the 345 HP Ram Air IV that were carried over from 1969.

The 455 engine available in the second generation Firebird Trans Am was arguably the last high-performance engine of the original muscle car generation. The 455 CID engine made its first appearance in the Firebird in 1971 as the round-port "455 HO", which continued through the 1972 model year. Pontiac offered the 455 through the 1976 model year, but tightening restrictions on vehicle emissions guaranteed its demise. Thus, the 1976 Trans Am was the last of the "Big Cube Birds," with only 7,100 units produced with the 455 engine. All 1976 Firebirds equipped with the 455 engine were also fitted with manual transmissions.

1971 was a carry-over year for Firebird. Very few changes were made since the previous year's new body style was launched so late in that model year. The major styling cue was the use of a new high-back bucket seat. The '72 UAW strike affected the Norwood, OH assembly plant, which produced Firebirds and Camaros. As a result, the yearly output of Firebirds was severely reduced this model year.

Since the Firebird was completely redesigned only two years ago, the changes for 1972 were of a very minor nature. And during the 1972 strike, the Firebird and the sister F-body Camaro were nearly dropped.

1973 was the last year of a 4-year styling cycle for the second generation Firebird. The five mph front bumper requirements for all U.S. cars in 1974 would see the end of the popular Endura-covered nose. Thus, for 1973, only the grille pattern was changed for visual effect, as it returned to a rectangular design. For the Trans Am a new vinyl hood applique, popularly referred to as the "screaming chicken," was offered up as a wildly popular option.

For 1974, new safety regulations forced the redesign of the front and rear bumper system in order to accommodate 5-mph energy-absorbing mechanisms. A new wraparound rear window was introduced. The Trans Am's new base engine was demoted to the venerable 400 cubic inch V8. Both the 455 and 455SD were optional again this year on the Formula and the T/A.

But in 1973 and 1974, a special version of the 455, called the "Super Duty 455" (SD-455), was offered. The SD-455 consisted of a strengthened cylinder block that included 4-bolt main bearings and added material in various locations for improved strength. Original plans called for a forged crankshaft, although actual production SD455s received nodular iron crankshafts with minor enhancements. Forged rods and forged aluminum pistons were specified, as were unique high-flow cylinder heads. A low compression ratio of 8.4:1 advertised (7.9:1 actual) yielded 290 SAE net horsepower. It should also be noted that production SD455 cars did not have functional hood scoops which could be made functional by removing the plate at the air inlet.