A series of arylidenehydrazides (3a-3i) were synthesized from [6-(4-bromophenyl)imidazo[2,1-b]thiazol-3-yl]acetic acid hydrazide. The structures of new compounds were determined by analytical and spectral (IR, (1)H NMR, (13)C NMR, EIMS) methods. The synthesized compounds (3a-3i) were evaluated in the National Cancer Institute's 3-cell line, one dose in vitro primary cytotoxicity assay. Compounds 3a-3c, 3h and 3i which passed the criteria for activity in this assay were scheduled automatically for evaluation against the full panel of 60 human tumour cell lines at a minimum of five concentrations at 10-fold dilutions. Compounds 3c demonstrated the most marked effects on a prostate cancer cell line (PC-3, log(10)GI(50) value<-8.00).