Staggered bilateral total knee arthroplasty (BTKA) performed 4 to 7 days apart has been shown to have fewer postoperative complications than sequential or staged BTKA. However, there has been no comparison of staggered BTKA with different intervals. A retrospective study involving 79 patients who underwent BTKA from 2002 to 2004 was performed to determine whether the interval between each TKA influenced the clinical outcome. Staggered operations performed 2 days (n = 46) or 7 days (n = 33) apart had similar incidence of major (acute myocardial infarction, pulmonary embolism, etc) and minor complications (transient hypotension or low Sp(o)(2)) throughout hospitalization. Perioperative complications in the first and second TKAs were similar when TKAs were performed with a 2- or a 7-day interval.