The present communication deals with a discussion on the significance of chromosome numbers in Charophyta. After presenting a brief review of the various views held on the basic chromosome numbers in the taxa ofChara, NitellaandTolypella, the role of polyploidy in the evolution of Charophyta and the possible ways in which polyploid taxa might have originated in nature have been considered. On the basis of present evidences aneuploids seem to show restricted geographical distribution as compared to euploids. Maximum degree of polyploidy has been found to be prevalent inChara zeylanicawithin the tribe Chareae andNitella tenuissimaandNitella furcatawithin the tribe Nitelleae. Significance of polyploidy in relation to sex, taxonomy, external form, chromosome length, pH, and altitude has also been discussed with some specific examples.