Abstract : This report describes the synthesis of new compounds for evaluation as antiparasitic agents. Most of the biological data pertain to activity against Trypanosoma rhodesiense but limited data pertaining to leishmania, filarius and plasmodium are also included. Biological data is included for compounds prepared in an earlier contract. The salts are derivatives of imidazole, pyridine, thiazole, benizimidazole and imidazo (1,2-a) pyridine. High levels of in vivo activity are reported for many of the compounds.