In this study, fifteen 2,3-disubstituted-4-thiazolidinone derivatives were synthesized by the reaction of Schiff bases and a-mercaptoacetic acid. The structures of the compounds were elucidated by IR, H-1-NMR, C-13-NMR, mass spectral data and elementary analysis. The antihist-aminic and anticholinergic activities of the compounds were determined by tests performed on isolated guinea pig trachea in comparison with aminophylline (CAS 317-34-0). Compound 15 (3-[3-(2-methyl-piperidine-1-yl)propyl]-2-(4-methyl- phenyl)thiazolidin-4-one hydrochloride) showed the highest inhibition (53%).