The purpose of our study was to investigate which radiological parameter had the maximal detrimental effect on functional outcome following malunion of distal radius fractures. Sixty-four women over 40 years of age who had sustained low-energy wrist fractures were included in the study. The mean age of the patients was 64 years. We compared the ulnar variance, radial inclination and palmar tilt of the fractured wrist to the non-injured contralateral side on radiographs obtained after fracture healing. The functional outcome was assessed at a mean follow-up of 28 months. Wrist mobility, grip strength, and pain with daily activities were determined and combined to give a final outcome rating. An increase in ulnar variance was found to be the most important radiological parameter affecting functional outcome and the outcome tended to be influenced by age, hand dominance and the presence of articular involvement.