We undertook a retrospective review of 78 percutaneous hip aspirations performed as a prerequisite to prosthetic revision or replacement. Although the majority of the patients were already scheduled for revision or replacement, many aspirations were requested as part of the "routine" algorithm in the evaluation of a painful hip. Cultures from the aspirated fluid were compared with those obtained intraoperatively (where possible) and to the clinical suspicion of infection. Many of the selected patients had clinical and/or radiographic indications of pain. Our results yielded no evidence of infection (0%) when there was no clinical suspicion of infection (60 patients). Clinical suspicion for infection was high in 7 patients; aspirates demonstrated infection in 5 of them. One aspiration was false negative for infection, but subsequent intraoperative cultures were positive. When the clinical suspicion was intermediate or equivocal (11 patients), results were negative in 9 and positive in 2, both at aspiration and intraoperatively. We contend that routine percutaneous hip aspirations do not need to be performed when a prosthetic revision or replacement is contemplated if the clinical suspicion for infection is low. Hip aspiration and arthrography should not be eliminated, however, when the clinical suspicion is equivocal or high or when there is no apparent cause for a painful prosthesis.