During the course of study searching for the antiparasitic agents from natural compounds, we found that curcumin showed cytotoxicity against African trypanosomes in vitro. The LD50 values of curcumin were 4.77±0.91μM for bloodstream forms and 46.52±4.94μM for procyclic forms of Trypanosoma brucei brucei (GUTat 3.1 clone).