Abstract Thiosemicarbazones are promising classes of compounds with antitumor activity. For this study, six 2,4-dihydroxy-benzylidene-thiosemicarbazones compounds were synthesized. These compounds were submitted to different assays in silico, in vitro and in vivo to evaluate the toxicological, antioxidant and antitumor effects. The in silico results were evaluated by the SwissADME and pkCSM platforms and showed that all compounds had good oral bioavailability profiles. The in vitro and in vivo toxicity assays showed that the compounds showed low cytotoxicity against different normal cells and did not promote hemolytic effects. The single dose acute toxicity test (2000 mg/kg) showed that none of the compounds were toxic to mice. In in vitro antioxidant activity assays, the compounds showed moderate to low activity, with PB17 standing out for the ABTS radical capture assay. The in vivo antioxidant activity highlighted the compounds 1, 6 and 8 that promoted a significant increase in the concentration of liver antioxidant enzymes. Finally, all compounds showed promising antitumor activity against different cell lines, especially MCF-7 and DU145 lines, in addition, they inhibited the growth of sarcoma 180 at concentrations lower than 50 mg/kg. These results showed that the evaluated compounds can be considered as potential antitumor agents. study 2,4dihydroxybenzylidenethiosemicarbazones 24dihydroxybenzylidenethiosemicarbazones dihydroxybenzylidenethiosemicarbazones 2,4 dihydroxy benzylidene thiosemicarbazones 2 4 synthesized toxicological effects profiles 2000 (200 mg/kg mgkg mg kg mice PB PB1 assay 1 enzymes Finally lines MCF7 MCF 7 MCF- DU DU14 addition 18 5 agents 4dihydroxybenzylidenethiosemicarbazones 24 2, 200 (20 DU1 20 (2 (