Limited joint mobility (LJM) of the small joints of the hands was studied in 63 adult insulin-dependent diabetics to determine whether LJM might serve as an indicator to the presence of diabetic retinopathy in diabetics of long duration. In 123 non-diabetic controls, and in the 63 diabetics, the prevalence of LJM increased with age. In the diabetics, LJM was not associated with retinopathy, long-term glycaemic control or HLA type. The hypothesis that LJM is useful as a predictor of the development of retinopathy in young diabetics does not extend to older diabetics of long duration. LJM and retinopathy may have a different pathophysiology.