Abstract: Alloxan dose for experimental induction of diabetes in rats has to be optimized. Lower doses can result in auto-reversion to normal state without medical help, while higher doses cause toxicity and loss of experimental animals. Induction of stable diabetes for prolonged period is needed for studies on various parameters in diabetes. Alloxan dose of 120, 140, 160 and 180 mg kg-1 body weight was given intraperitonealy to experimental rats in groups of 6 animals for each dose. The blood glucose, urine glucose, liver glycogen level and variation in body weight were studied. Alloxan toxicity to the kidney was evaluated histologically. OGTT (Oral Glucose Tolerance Test) was performed to determine the correct diabetic status of the animals. Lower doses up to 140 mg kg-1 body weight induce diabetes, however animals revert back to normal blood glucose values in a week. Alloxan dose of 160 mg kg-1 body weight can demonstrate stable diabetes and animals survive for months. While animals treated with 180 mg kg-1 body weight show severe diabetes, high mortality rate and damage to kidneys. A dose of 160 mg kg-1 body weight is suitable for induction of stable diabetes.