Despite lack of any studies, to our knowledge, bilateral total hip arthroplasty (THA) is believed to carry higher perioperative mortality. The purpose of this study is to investigate the incidence of mortality within 90 days of bilateral THA in a major urban medical center. The incidence of 90-day mortality after 1-stage bilateral THA performed in 707 patients between 1995 and 2004 was evaluated. A detailed analysis of our database was performed to determine which bilateral THA patients died within 90 days of surgery. Every living patient who had undergone bilateral hip arthroplasty was contacted. One patient (0.14%, 1/707) died within 90 days of 1-stage bilateral THA. The patient developed spontaneous retroperitoneal hematoma requiring massive transfusion. The patient died of multisystem failure 35 days after undergoing bilateral THA. One-stage bilateral uncemented THA performed in a select group of healthy and young patients carries an acceptable risk.