Background Revision THAs are expected to increase; however, few studies have characterized the prognosis of revision THAs in younger patients. Questions/purposes We performed a case-control study to evaluate intermediate-term survivorship, complications, and hip and activity scores after revision THAs in patients 55 years and younger, compared these outcomes with the results of primary THAs in a matched patient population, and evaluated risk factors for failed revisions.Methods Ninety-three patients (103 hips) had a minimum of 4 years after revision THA, died, or had rerevision surgery. They were matched with 98 patients (103 hips) with primary THAs. Survivorship, complications, and clinical outcomes were compared between the groups using t-tests. Risk factors for failure also were assessed with chisquare analysis.