Earlier we have reported the antidiabetic activity of fresh juice of rhizomes of Zingiber officinale(Z. officinale) and its correlation with 5-HT receptor antagonism. Since 6-gingerol the markercompound of Z. officinale is reported to posses 5-HT anatgonistic activity, the presentinvestigation, was undertaken to find out the concentration of 6-gingerol present in methanolicextract of Z. officinale and its different fractions (petroleum ether, toluene and chloroform). Wealso evaluated these fractions for antidiabetic activity in streptozotocin (STZ)-induced neonataltype 2 diabetic rats. Fasting glucose and insulin levels in non insulin dependent diabetes mellitus(NIDDM) rats were found to be significantly (P < 0.05) higher than control rats and these weresignificantly decreased by treatment with methanolic extract of Z. officinale and its fractions. Theresults of oral glucose tolerance test (OGTT) showed that methanolic extract and its fractionssignificantly (P < 0.05) decreased both STZ-induced increase in AUCglucose and AUCinsulin values inNIDDM groups. Treatment with petroleum ether fraction produced a greater reduction inelevated glucose and AUCglucose levels as compared to treatment with other fractions. Treatmentwith methanolic extract of Z. officinale and its fractions also produced significant reduction in theelevated lipid, serum glutamate oxaloacetate transaminase (SGOT) and serum glutamatepyruvate transaminase (SGPT) levels in NIDDM rats. The effect of petroleum ether fraction onelevated lipid, SGOT and SGPT levels was significantly greater as compared to treatment withother fractions. The concentration of 6-gingerol was found to be maximum in petroleum etherfraction (11.430%) and minimum in chloroform fraction (0.973%). The methanolic extract andtoluene fraction was found to contain 3.080% and 2.191%, 6-gingerol respectively. In conclusion,our data suggest that methonolic extract and its fractions possess significant antidiabetic activityin NIDDM rats. The extent of activity appears to be dependent on the concentration of 6-gingerolpresent in the extract or its fractions.