A series of 3-(5-(arylidene)-2-(aryl)-4-oxothiazolidin-3-yl)-2-phenylquinazolin-4(3H)-one derivatives (1-18) was synthesized in appreciable yield and characterized by physicochemical and spectral means. The synthesized compounds were evaluated for their in vitro antimicrobial and anticancer potentials. Antimicrobial properties of the title compounds were investigated against Gram positive and Gram negative bacterial as well fungal strains. 3-(5-(3- Methoxybenzylidene)-2-(4-(dimethylamino)phenyl)-4-oxothiazolidin-3-yl)-2-phenyl quinazolin-4(3H)-one (16, pMICam = 1.71 µM/ml) was found to be the most active antimicrobial agent. The anticancer evaluation of synthesized compounds against human colon (HCT116) cancer cell line indicated that 3-(5-(4-bromobenzylidene)-2-(3-chlorophenyl)-4- oxothiazolidin-3-yl)-2-phenylquinazolin-4(3H)-one (7, IC50 = 5.27 µM) was the most active anticancer agent and was more potent than standard drug, 5-fluorouracil (IC50 = 6.00 µM). QSAR models developed for antimicrobial activity of synthesized compounds indicated that antimicrobial activity of synthesized 4-thiazolidinone derivatives was governed by the topological parameters, valence first and second order molecular connectivity indices ((1)Χ(v) and (2)Χ(v)) and the electronic parameters, total energy (Te) and cosmic energy (Cos E).