Background: Hip preservation surgery has become more commonplace, yet when it fails, it is unclear why it does so. Understanding failed procedures should lead to improved surgical results. Questions/purposes: The purposes of this study were to (1) characterize patients undergoing hip preservation surgery after prior procedures; (2) compare demographics, hip pain, and function in patients with prior procedures with those undergoing primary surgery; (3) determine the types of previous procedures and the reasons for secondary surgery; and (4) report the procedure profile of the secondary surgeries. Methods: A prospective, multicenter hip preservation database of 2263 patients (2386 surgery cases) was reviewed to identify 352 patients (359 hips, 15% of the total) who had prior surgery. Patient demographics, type of previous surgery, diagnostic categories, clinical scores, and type of secondary procedure were recorded. Results: For patients undergoing secondary surgery, the average age was 23 years and 70% were female. Hip pain and function were similar between patients undergoing primary and secondary surgery. The previous surgical approaches were open in 52% and hip arthroscopy in 48%. In the femoroacetabular impingement and adult acetabular dysplasia subgroups, hip arthroscopy was the most common previous surgical approach (86% and 64%, respectively). Inadequately corrected structural disease was the most common reason for secondary surgery. Femoral osteochondroplasty and acetabular reorientation were the most common secondary procedures. Conclusions: Inadequately corrected structural disease (femoroacetabular impingement or acetabular dysplasia) was commonly associated with the need for secondary hip preservation surgery. Although we do not have data to identify other technical failures, the available data suggest primary treatments should encompass comprehensive deformity correction when indicated. Level of Evidence: Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.