In order to assess the relation between limited joint mobility (LJM) and peripheral nerve function in diabetic children, peroneal nerve amplitude and motor conduction velocity as well as sural nerve amplitude and distal latency were measured with a Medelec MSG electromyograph. LJM was examined by observing the hands in the prayer position of 60 unselected diabetic children (average age 11.2 +/- 3.1 years; mean duration of diabetes 4.1 +/- 3 years) and 31 healthy controls. Of 60 patients, 38.3 percent had limited joint mobility. no influence of sex on expression of LJM was found. Its appearence was influenced by age, duration of diabetes and metabolic control (HbA1c) (p < 0.001, p < 0.001, p < 0.001, respectively). The mean amplitude, nerve conduction velocity and distal latency values in diabetic children with LJM were slower than these in the normal control group (peroneal amplitude p < 0.01, peroneal MCV p < 0.001, sural amplitude p < 0.001, sural distal latency p < 0.001). Of four patients with stage IV LJM, three had symptomatic neuropathy diagnosed using the criteria suggested by Dyck. Consequently, LJM identifies a population at risk for development of diabetic neuropathy. Thus, being easy and sensitive, LJM determination may provide both the physician and the patient himself with an important motivation to improve diabetic control in an effort to prevent dibetic neuropathy.