A cross-sectional survey with the aim to study the prevalence of diabetes and long-term complications was carried out in a health care district in Sweden with 125,500 inhabitants. Information was extracted from the medical records. 4127 people with diabetes were identified of whom 87% were classified as NIDDM (non-insulin-dependent diabetes mellitus), 12% as IDDM (insulin-dependent diabetes mellitus) and 0.7% as secondary or unclassified diabetes. The prevalence of diagnosed diabetes was 3.3%. A total of 83% received their regular routine care at primary health care centres, 31% were treated with diet only, 36% had oral hypoglycaemic agents, 31% had insulin and 2% had combination therapy. The mean HbA1c was 7.2% (ref. range 4.0-5.3%). Of the adults (> 18 years) 27% had retinopathy, 13% had nephropathy and 27% had loss of pallaesthesia. 50% had hypertension, 21% angina pectoris, 11% had had myocardial infarction, 11% stroke, 21% had signs of peripheral arterial disease, 2% had been amputated and 21% were smokers. The conclusion is that in a population of patients with diabetes with acceptable metabolic control, complications are still a great problem.