Objective: to investigate the anti diabetic effect of the bitter melon on Alloxan induced diabetes in experimental animals (rabbits). Materials and Methods: the alcohol extract of whole fruit was tested for its efficacy in Alloxan (150mg/kg) induced diabetic rabbit. The diabetic rabbits were divided into 5groups. Group I (control) received 2% gumacasia, groupie (positive control) received standard drug Metformin (62.5mg+2%GA), group III, IV, V (T1 T2 T3) were treated orally with a daily dose of 0.5(gm) 1gm, 1.5gm respectively for 35 days, for all diabetic rabbits after giving TEST,NC,PC preparations, the blood samples were collected and determined the blood glucose level 0,1,3,24hrs intervals. 0hr reading is before drug giving and remaining 3 readings after drugs giving. 24th her reading is considered as 0hr reading for the next day. Results: administration of alcohol of an extract of bitter melon produced a dose dependent decrease in blood glucose levels in Alloxan induced rabbits. There was a significant fall in blood sugar level in High dose (1.5GM/kg) in comparison to low dose (0.5gm/kg) and median dose (1gm/kg) shown by LSD test. This is comparable to the effect of Metformin. Conclusion: the results of this study show that chronic oral administration of an extract of Momordica charantia fruit at an appropriate dosage may be good alternative anti diabetic agent.