The hypoglycemic and hypolipidaemic effects of fenugreek seeds (Trigonella foenum graecum) arewell established. Owing to the wide spread use of the seeds by healthy individuals and bydiabetic patients we wanted to test whether the seeds can affect biological systems such asmembrane transport function. In the present study fenugreek seed polyphenols were extractedand their effect on erythrocyte membrane-bound sodium-potassium adenosine triphosphatase(Na+/K+-ATPase) activity was studied in vitro. Fenugreek seed polyphenols inhibited Na+/K+-ATPase in erythrocyte membrane of diabetic and normal subjects. Maximum inhibition was observed at100 ml of extract containing 0.75 mM gallic acid equivalents. The uncoupling of membrane ATPases invitro suggest that polyphenols from fenugreek seeds may possess a positive inotropic effect.