Sacroiliac joint (SIJ) dysfunction is once again garnering attention as a treatable diagnosis for the millions of individuals suffering from acute and chronic low back pain. Theoretically, excessive or restricted motion at the SIJ can alter the mechanics of the spine and pelvis causing pain. Oft en the clinician's history and physical examination are nonspecific in the evaluation of low back pain and a high index of suspicion is required to consider SIJ dysfunction as the cause for the patient's symptoms. Multiple physical examination maneuvers exist to detect SIJ dysfunction, but none are individually sensitive or specific enough to diagnose SIJ dysfunction alone. The clinician should learn 3 to 5 tests that can easily be performed and replicated for the evaluation of SIJ dysfunction and use them consistently in patients presenting with low back pain. Sacroiliac joint anesthetic blocks using computed tomography (CT) or fluoroscopic-guided injection are considered the gold standards for diagnosing SIJ dysfunction as the cause for nonspecific low back pain. Imaging studies and laboratory evaluations are generally unnecessary for the diagnosis of SIJ dysfunction unless specific elements of the history and physical suggest alternate etiologies. Interventions to treat the pain of SIJ dysfunction include nonsteroidal anti-inflammatory drugs (NSAIDs), physical therapy, corti costeroid injections, osteopathic manipulation, radiofrequency denervation, SIJ belts, and surgery. While there are few high-level evidence studies evaluating and comparing these treatments in individuals with SIJ pain, patients may respond to one, or a combination of these treatments.sarcoiliac joint; sarcoiliac joint dysfunction; spine; low back pain.