The aim of this study was to compare two surgery methods including radial shortening and radial shortening combined with vascularized bone graft for treatment of stage II or IIIa of Kienböck's disease. It is a randomized, controlled clinical trial, which was carried out in 2011–2013. Twenty-four patients were assigned equally to radial shortening group (A) or radial shortening combined with vascularized bone graft group (B). The outcome was assessed by Mayo Wrist score before and 9 months after surgery. The mean Mayo Wrist score (SD) was 27.1 (15.4) and 32.5 (18.3) before surgery and 74.6 (5.4) and 85.8 (5.1) after surgery for groups A and B, respectively. The mean score increased in both groups, and it was higher in group B significantly. Radial shortening combined with vascularized bone graft is a valuable method which can be more effective than radial shortening alone, in early stages of Kienböck's disease. This trial is registered with IRCT201404127841N5.