A series of 3, 7-dimethyl-pyrazolo [3, 4-e][1, 2, 4] triazin-4-yl thiosemicarbazide derivatives 3– 22 were prepared and evaluated in vitro against HM1: 1MSS strain of Entamoeba histolytica, to identify the compounds for antiamoebic activity. They exhibited antiamoebic activity in the range (IC50= 0.81–7.31 μM). The results were compared to the activity of known drug metronidazole. It is inferred from the in vitro studies that the compounds 10, 11, 17 and 18 ...