The author treated since 1985 on a long-term basis (for more than one year) 228 diabetic patients with an insulin pump. She gives an account for her experience of three years' treatment of 32 diabetics type 1 and 2, incl. 5 treated already for a period of 5 years. Eight type 1 diabetics treated on account of a great lability of the disease are free from specific complications. In 10 type 1 diabetics treated on account of developing nephropathy and neuropathy the condition has stabilized and does not develop further. In 14 type 2 diabetics progression of complications which led to the indication of pump treatment did not occur. Treatment had the most favourable effect on sensitive neuropathy and incipient nephropathy where a reduction of proteinuria was recorded. From the total number of 228 patients treated on a long-term basis in 31, on failure of the pump, decompensation occurred. Five of these patients developed ketosis which called for hospitalization. Clinically severe hypoglycaemia was observed only once.