Scapholunate instability can result in debilitating pain, dysfunction, and secondary arthritis. Diagnosis is primarily based on a combination of clinical and radiological parameters. However, wrist arthroscopy is regarded as the gold standard for definitive confirmation to identify the extent of a scapholunate instability, with specific attention to the integrity of the extrinsic ligamentous system, which is probably more important than the intrinsic ligament. We discuss how to perform a step-by-step, comprehensive, and complete arthroscopic assessment of the entire scapholunate complex.