Fourteen novel 1,2,4-triazole Schiff bases containing the 1-[bi-(4-fluorophenyl)methyl]piperazine group were prepared, in good yield (73–85 %), in five steps starting from 1-[bi-(4-fluorophenyl)methyl]piperazine and ethyl chloroacetate, with use of microwave irradiation. The structures of the new compounds were characterized by IR spectroscopy, MS, 1H and 13C NMR spectroscopy, and elemental analysis. Assay of the newly prepared compounds for bioactivity against tumor cells revealed that the most of the compounds had good to excellent inhibitory activity against CDC25B (99.70 % inhibition). The 4-amino-5-[4-bi-(4-fluorophenyl) methylpiperazin-1-ylmethyl]-1,2,4-triazole-3-thione group was found to be beneficial group improving anti-tumor activity to some extent.