Background Traumatic posterior dislocation of the hip joint usually results from high-energy trauma, which can cause additional injuries that may need to be addressed after reduction. Purpose This study was undertaken to present arthroscopic findings after traumatic posterior hip dislocation in patients with mechanical hip symptoms. Study Design Case series; Level of evidence, 4. Methods All patients treated with hip arthroscopy between 2002 and 2006 for mechanical hip symptoms after traumatic posterior hip dislocation with subsequent closed reduction were included in this study. The time between closed reduction and arthroscopy, arthroscopic findings and treatment, preoperative and last follow-up WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) scores, and last follow-up radiographs were analyzed. Complications or the need for further surgical treatment are reported. Results There were 17 patients (13 male, 4 female) with an average age of 28.5 years (range, 19-37 years). The average time between closed reduction and arthroscopy was 3 months. Fourteen patients had anterior labral tears, 6 had posterior labral tears, 16 had acetabular chondral damage, all had femoral chondral damage, and 14 had intra-articular fragments. The preoperative WOMAC score was 46; the last follow-up (average 45 months) WOMAC score was 87 (range, 45-93); this was considered statistically significant (P = .001). One patient required total hip replacement for osteoarthritis and 1 presented with osteonecrosis and is waiting for hip replacement. Conclusion The clearest indication for arthroscopy after traumatic posterior hip dislocation was loose fragments inside the joint. Arthroscopy was also performed in every patient with mechanical hip symptoms. Intra-articular damage was demonstrated in every case. Most of the patients had significant improvement after hip arthroscopy.