Quantitative structure activity relationship studies have been conducted on a series (24 compounds) of sulfonamide derivatives with selective carbonic anhydrase inhibitory activity using ChemOffice v.8.0 software. The best predictions have been obtained for hCA-II enzyme inhibition activity (Q(2) = 0.552, r(2) = 0.724) and with hCA-VII enzyme inhibition activity (Q(2) = 0.501, r(2) = 0.704). Both equations are validated by a test set of compounds and give satisfactory predictive r(2) values of 0.434, and 0.608, respectively. The equations selected emphasized the importance of LogP (octanol/water partition coefficient). Highest Occupied Molecular Orbital (HOMO) and Radius of gyration (Rgy) on biological activity i.e., hydrophobic groups, presence of electron donating groups, size and shape of molecule might be influencing the selective carbonic anhydrase inhibitory activity.