Distinguishing intracapsular and extracapsular hip infections may be clinically difficult. Because of this difficulty in diagnosis, the spread of an extracapsular infection into the hip joint may be missed and lead to significant joint destruction. The case of a patient who suffered from the spread of adductor pyomyositis to the hip joint is reported. The delay in diagnosis of an intracapsular hip infection led to significant intra-articular destruction and ultimately necessitated a Girdlestone resection arthroplasty. The patient's hip function was salvaged with a total hip arthroplasty. The presence of an extracapsular hip infection should mandate serial physical examinations and aggressive evaluation to rule out intracapsular spread. A delay in diagnosis of an intracapsular hip infection can lead to catastrophic results.