The aim of this study was to evaluate the effect of a structured teaching/treatment programme on the clinical and metabolic control of non-insulin-dependent (type 2) diabetic patients. The programme was aimed at improving the overall treatment quality in these patients through measures involving self-care, diet, exercise and weight reduction. Four theoretical-practical teaching units were given once a week to group of 5-8 ambulatory patients by previously trained general practitioners. Clinical and biochemical parameters were recorded at the beginning of the course and 1 year after its completion in 40 patients attending the programme and in 39 patients of similar clinical characteristics under conventional diabetes treatment, but receiving no structured teaching before or during the survey period (control group). The drop-out percentage in the intervention group (25%) was significantly lower than in the control group (45%, P < 0.05), suggesting an incentive toward greater compliance in the former. At the end of the 1-year follow-up, the mean differences observed in the control and in the intervention groups were: body weight loss -2.4 +/- 0.5 kg vs -0.4 +/- 0.5 (P < 0.001); haemoglobin HbA1 -0.2% +/- 0.4% vs +0.8% +/- 0.4% (NS); number of daily oral hypoglycaemic agent intake -1.4 +/- 0.2 vs +0.9 +/- 0.2 tablets (P < 0.001). Our results strongly suggest that this programme, applied through family doctors, may constitute an efficient tool to improve the compliance and clinico-metabolic control of type 2 patients at the primary health care level.