Analogs of I,S-diaminopropane as inhibitors for the growth of Leishmania donovani have been synthesized and evaluated,for their antileishmanial activity. Of the many active compounds, 1-(3-N,N-bis methoxycarbonyl guanidino)propyl-4-methylpiperidine piperazine (4e,f) exhibited significant in vivo inhibitory efficacy against L. donovani by oral and intraperitoneal route of administration. (C) 1997 Elsevier Science Ltd.