Subspine impingement (SSI) is a form of extra-articular hip impingement caused by abnormal contact between the anterior inferior iliac spine (AIIS) and the femoral neck during hip flexion. Often occurring alongside femoroacetabular impingement (FAI), SSI can contribute to persistent hip pain, limited range of motion, and mechanical symptoms. Diagnosis relies on a combination of patient history, physical examination, advanced imaging (computed tomography [CT] or magnetic resonance imaging [MRI]), and dynamic testing. Conservative treatment may provide symptom relief, but refractory cases often benefit from arthroscopic decompression of the AIIS. Early recognition and targeted management of SSI are critical to prevent progression of intra-articular damage and optimize patient outcomes.