Several quinolines were synthesized and evaluated in vitro and in vivo against the nematodes Caenorhabditis elegans, Heligmosomoides polygyrus and the protozoa Trichomonas vaginalis. If some of them have shown in vitro nematocide activity (at 10 microM), however, their trichomonacidal activity reached 50% reduction at only 100 microM. The in vivo activity on Trichinella spiralis model was evaluated for some of the most in vitro active quinolines.