Built on the location of the historic Montgomery Block, it has a structural height of 260 meters (853 ft) and contains 48 floors of retail and office space. Construction began in 1969 and finished in 1972. It is currently ranked as the 100th tallest building in the world. Transamerica moved their headquarters to the new building from across the street, where they used to be based in another pyramid-shaped building now occupied by the Church of Scientology of San Francisco.
Its unique shape is the result of the desire by Transamerica to have a building whose top would be looked up to by the executives on the highest floor of the 555 California Street, which is not only tall but also sits upon a substantially higher elevation. The land use and zoning restrictions for the parcel limited the number of square feet of office that could be built upon the lot, which sits at the northern boundary of the financial district. The pyramid is an innovative solution to this design challenge, and when viewed from the East Bay forms a prominent and unique skyline projection, forming an important element of San Francisco's "signature skyline".
Although it no longer houses the headquarters of the Transamerica Corporation, it is still strongly associated with the company and is depicted in the company's logo. The building is evocative of San Francisco and has become one of the many symbols of the city. Designed by architect William Pereira, it faced considerable opposition during its planning and construction, and was sometimes referred to by detractors in derogatory slang.
The building is a tall, four-sided pyramid with two "wings" on opposite sides of the building. The wing to the east of the building contains an elevator shaft, while the wing to the west contains a stairwell and a smoke tower. The top 64.6 meters (212 ft) of the building is the spire. There are four cameras pointed in the four cardinal directions at the top of this spire forming a virtual observation deck. Four monitors in the lobby, whose direction and zoom can be controlled by visitors, display the cameras' views 24 hours a day. An observation deck on the 27th floor was closed after the September 11, 2001 attacks, and replaced by the virtual observation deck. The top of the Transamerica Pyramid is covered with aluminum panels. During the holiday season, Thanksgiving, and 4th of July, a bright, white light is lit on top of the pyramid.
The Transamerica Pyramid was the tallest skyscraper west of the Mississippi from 1972–1974 (surpassing the nearby 555 California Street), at which point it was surpassed by the Aon Center in Los Angeles, which was designed by Pereira's former business partner Charles Luckman.
The building is considered to have been the intended target of a foiled terrorist attack, involving the hijacking of airplanes as part of Oplan Bojinka, which was foiled in 1995.