Anterior iliopsoas impingement and tendinitis is a poorly understood and likely underrecognized cause of groin pain and functional disability after total hip arthroplasty. The patient history and physical examination findings are usually only suggestive, and the symptoms frequently subtle. The diagnosis may be confirmed by one or more imaging studies, including a cross-table lateral radiograph, computed tomography, magnetic resonance imaging, and ultrasonography, in combination with a confirmatory diagnostic injection. Nonsurgical management may not resolve the problem. Surgical treatment, consisting of release or resection of the iliopsoas tendon, alone or in combination with acetabular revision for an anterior overhanging component, usually provides permanent pain relief.