This study examined the association between limited joint mobility (LJM) and diabetic control, atherosclerotic vascular disease and other diabetic complications in non-insulin-dependent diabetic (NIDDM) patients. LJM was studied in 139 [age (mean +/- SD) 61.3 +/- 12.3 years] NIDDM patients. Limitation of several joints was examined with a goniometer and LJM was classified by the Rosenbloom method. The NIDDM patients were examined for the following diseases: history of myocardial infarction, coronary heart, cerebrovascular and peripheral vascular diseases. The diabetic complications, background and proliferative retinopathy, nephropathy, and neuropathy, were also assessed. The metabolic control of the diabetes was evaluated by the average glycosylated hemoglobin Alc (GHbA kappa) concentration and lipid values were also measured. Mean levels of GHbAlc were 8.9 vs. 8.2% (p < 0.05) in NIDDM patients with and without LJM. NIDDM patients with LJM had a 3.1- (95% confidence interval, 1.2-7.7) and a 4.0-fold risk (95% confidence interval, 1.2-13.0) for coronary heart and cerebrovascular disease respectively, when the confounding effects of age, duration of diabetes and control of diabetes were controlled using stepwise logistic regression analysis. Patients with LJM had a 9.3- (95% confidence interval, 1.1-79.0) and a 3.3-fold risk (95% confidence interval, 1.0-10.5) of proliferative retinopathy and nephropathy respectively, when the confounding effects of age and duration of diabetes were controlled, but the correlation disappeared when control of diabetes was included in the model. In conclusion, the presence of LJM is associated with the control of diabetes and with the presence of coronary heart and cerebrovascular diseases in NIDDM patients.