Construction was completed and first occupancy commenced. For the next two years, the 853-foot-high Pyramid (260 meters) was the tallest building in the United States west of the Mississippi River.  It remains Northern California’s tallest building.

The 7.1-magnitude Loma Prieta earthquake struck the Bay Area. Although the 48-story Pyramid shook for more than a minute - during which its top story swayed almost a foot from side to side - the building was undamaged and no one was seriously injured. The structural performance of The Transamerica Pyramid under such intense conditions can be attributed to the building's careful structural engineering, designed to withstand tremors in the seismically active Bay Area.

Unrelated to the earthquake, as part of a strategic self-directed reorganization Transamerica Corp. relocated its headquarters from San Francisco. The company does, however, maintain a small presence as a tenant of the building to this day and continues to use the building's image as its registered trademark logo.

Transamerica Corp. was acquired by AEGON USA, Inc., a wholly owned subsidiary of AEGON N.V., the third-largest international insurance organization worldwide (by market capitalization). Based in the Netherlands, AEGON also ranks in the top 10 insurance groups (listed by assets). With five major country units and businesses in several other countries, AEGON employs more than 20,000 people across the globe. AEGON continues to hold the building as an investment, although it later sold the non-financial service operations of Transamerica. Transamerica Corp.'s financial service products are still marketed worldwide under The Transamerica brand and the company continues to use The Transamerica Pyramid logo as its registered trademark.

The observation deck on the 27th floor was closed to public access, and the entrance inside the building was limited to tenants and their approved guests.