Forty-two women with thumb base osteoarthritis referred to a joint protection programme (JP) were distributed into groups: one with only JP (Control group) and one with addition of splints day/night, hot pack/home exercise (SE group). Assessments of pain, stiffness, grip force, disabilities of daily activities were performed before treatment, 1 week and 1 year after treatment. The SE group had a significant decrease in pain, stiffness and an improvement in daily activities directly after the intervention and at 1-year follow-up compared to the Control group. In the SE group pain at night, pain on motion, and stiffness decreased. Grip force increased and daily activities improved. The Control group decreased in pain on motion and showed improvement in daily activities just after the intervention but not at 1-year follow up. This comparative study shows that when splinting and exercise regimen are added to a JP programme it gives a greater improvement of pain, stiffness, grip force and daily activities than the JP programme alone.