Kienböck’s disease was described more than a century ago, the treatment for Kienböck disease still remains controversial. Ulnar variance is determined on a posteroanterior radiograph of the wrist obtained with the forearm in neutral rotation. Negative ulnar variance may increase shear forces across the lunate and predispose patients to developing lunate avascular necrosis (AVN). Vascular (early), osseous (intermediate) and chondral (late) are the three pathological phases of AVN. The diagnosis of Kienböck disease requires a high index of suspicion, particularly in young males presenting with pain and stiffness in the dominant wrist. A brief discussion on etiology, staging, classification and treatment of Kienböck’s disease has been provided in this chapter.