A new series of 5-[2-(2-methylprop1-enyl)-1H benzimidazol-1yl]-4,6-diphenyl-pyrimidin-2-(5H)-thione derivatives [3a-q] has been synthesized and subjected to evaluate their antibacterial properties. All the synthesized compounds of the series displayed, remarkable activity in comparison to standard drug (ampicillin). A number of descriptors were tested to adjudge a quantitative correlation between activity and structural features. However, significant correlations have emerged between activity and physicochemical parameters viz. polarizability parameter (MR). Moreover, results are interpreted on the basis of multiple regression and cross-validation methodology.