AbstractA series of bis‐naphthoquinone derivatives prepared by condensation of aryl aldehydes with lawsone were tested for antiparasitic activities against Toxoplasma gondii and Trypanosoma brucei parasites. Monofluorophenyl derivative 1a, 3,4‐difluorophenyl analog 1c and furyl compound 1l exhibited significant activity against T. gondii cells and appear to be new promising drug candidates against this parasite. The 3,4,5‐trifluorophenyl derivative 1g and the isovanillyl derivative 1j displayed selective activity against Leishmania major amastigotes.