The hands of 299 diabetic patients with and 161 without retinopathy were examined forabnormalities. Almost all abnormalities were finger joint contractures resulting in limited joint mobility (LJM) and/ or Dupuytren's contractures (DC). Both LJM and DC occurred not only in insulin-dependent diabetes (IDDM) but also in non-insulin-dependent diabetes (NIDDM). In retinopathy patients LJM and DC occurred in 48% and 36% of patients, respectively, compared with 24% and 16% in those without retinopathy. These differences were statistically significant (P < 0.001). The higher prevalence of LJM in the retinopathy group affected mainly those with severe retinopathy, there being no difference between background and nonretinopathy patients. DC was less clearly related to severe retinopathy. LJM was more severe in those with than without retinopathy. LJM and DC were also related to age and duration of known diabetes. Subgroups matched for age and duration of known diabetes showed that the main relationship of hand abnormalities was to retinopathy inIDDM, but more to age and duration of known diabetes in NIDDM.