The aims of this study were to undertake a prospective randomised trial to compare functional outcome, and range of motion after treatment of medial collateral ligament injuries by either early unprotected mobilisation or mobilisation with a hinged brace. Patients were randomised into either unprotected mobilisation or mobilisation with a hinged brace. Assessments occurred at 2 weeks, 6 weeks, 3 months and 6 months. Outcome measures included validated questionnaires (International Knee Documentation Committee and Knee Injury and Osteoarthritis Outcome Score scores), range of motion measurements and strength testing. Eighty six patients (mean age 30.4) were recruited. There were 53 men and 33 women. The mode of injury was sport in 56 patients (65%) with football, rugby and skiing being the most common types of sport involved. The mean time to return to full weight bearing was 3 weeks in both groups. The mean time to return to work was 4.6 weeks in the braced group and 4.1 weeks in the non-braced group (p=0.79). Return to running was at a mean of 14.3 weeks in the braced group and 12.8 weeks in the non-braced group (p=0.64). Return to full sport was 22 weeks in the braced group and 22.1 weeks in the non-braced group (p=0.99). There was no significant difference in range of movement or pain scores between the two groups at 2,6,12 and 24 weeks. The use of a hinged knee brace does not influence recovery after a medial collateral injury.