A reproducible and reliable HPTLC method for the indirect determination of gymnemic acids as gymnemagenin in Gymnema sylvestre plant has been reported. As gymnemagenin, a common aglycone of gymnemic acids, lacks in conjugation, very poor UV absorption is observed. So post-derivatzation method was used for quantification of gymnemagenin. Linearity was observed in the range of 180 – 1440 ng/spot. Thus the method was found to be more sensitive where gymnemagenin was quantified at nanogram level. The method was validated as per ICH guidelines and successfully applied for quantification of gymnemagenin from plant leaf powder, extract and poly herbal marketed formulation. Percentage recovery was found to be 98.4 ± 1.0%.