¹Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Istanbul University, Fatih 34116 Istanbul, Turkey DOI : 10.29228/jrp.21 Some new derivatives of 2-aryl-1,3-thiazolidin-4-one derivatives were produced (3a-p and 4a-p) in the search of potentially active new molecules with antitumor features. Compounds were obtained by cyclocondensation of 2-hydroxy-2,2-diphenyl-N-[(substituted phenyl)methylene]acetohydrazides (2) and mercaptoacetic acid or 2-mercaptopropionic acid. Identification and characterization of 32 new 2-aryl substituted thiazolidin-4-ones were performed with spectral and elemental analyzes. Compound 3c, 3g, 3j, 4g, 4n, and 4p were chosen as prototypes and assayed for their anticancer activity against diverse several cancer cell lines with in vitro primary anticancer test in the National Cancer Institute. Compound 4g exhibited significant anticancer activity with the inhibition value 84.19% against a leukemia cell line MOLT-4 while compound 4p had a remarkable inhibition ratio (72.11%) against the growth of a CNS (central nervous system) cancer cell line SF-295 in the primary screen. These preliminary and important results indicated that the compounds carried 2-aryl-1,3-thiazolidin-4-one scaffold can be evaluated as potentially promising anticancer agents. Keywords : 1,3-Thiazolidin-4-one; benzilic acid; mercaptoacetic acid; 2-mercaptopropionic acid; anticancer agents