ABSTRACT The insulin secretion pattern of the isolated perfused pancreas of the non-diabetic Chinese hamster after stimulation with glucose and tolbutamide is described. Stimulation with 100–800 mg glucose/100 ml leads to an increasing acute insulin secretion. The initial insulin peak reaches its maximum 2–3 min after the beginning of the stimulation with glucose. The amount of insulin initially secreted from the pancreas of fasted hamsters is larger than that of fed animals. The initial insulin peak is followed by a second short-term insulin release. The maximum of the second peak occurs approximately 10–15 min after the initial stimulation with glucose. With 100 mg glucose/100 ml the insulin secretion proceeds in a practically linear manner for a period of 140 min. With 200 and 400 mg glucose/100 ml the insulin secretion remains linear for approximately 80 min. With 200 mg glucose/100 ml about 10 000 μU insulin are secreted within 120 min, with 400 mg glucose/100 ml approximately 20 000 μU are secreted in the same period of time. The insulin secretion is described following repeated short-term stimulation with 200 mg glucose/100 ml and increasing glucose concentrations up to 500 mg/100 ml for 5 min each. In perfusion studies with 400 mg glucose/100 ml and 8 mg puromycin/100 ml the amount of insulin secreted in 150 min is reduced by about 50%. The insulin secretion stimulated by 100 mg glucose/100 ml was greatly increased by 10 mg tolbutamide/100 ml. The insulin secretion pattern at a glucose concentration of 50 mg/100 ml is shown following repeated stimulation with 10 mg tolbutamide/100 ml alternating with tolbutamide-free resting phases of 10 min. The mechanism of insulin secretion following stimulation with glucose and β-cytotrophic antidiabetics is discussed. The isolated perfused pancreas of the Chinese hamster is suitable for the study of the dynamics of insulin secretion.