The role of a community-based screening programme for microvascular complications of diabetes and hypertension was evaluated in the semi-rural town of Trowbridge (population 31,000). Of 405 diabetic patients identified (prevalence 1.31%), 358 (88%) attended for screening, 94 (26%) of whom were under hospital review for diabetes. In only 136 patients (38%) were all aspects of diabetes care found to be satisfactory. The remaining 222 patients included 162 patients with poor metabolic control (HbA1 greater than or equal to 12%), 118 who were hypertensive at screening, 13 with previously undiagnosed diabetic nephropathy, and 29 with undiagnosed potentially sight-threatening retinopathy. Overall standards of diabetes care in this community population appear inadequate, and might be improved by introduction of a simple screening programme for diabetic complications.