Summary A 24-year case history is reported of two consecutive tryparsamide-resistant second stage trypanosome infections in a white man. The first infection was cured after five years of treatment with 93 injections totaling 118.5 gm. of tryparsamide, 16.5 gm. of Bayer 205 and 3.5 gm. of tartar emetic. The second infection, occurring four years after the first cure, resisted 130 injections totaling 140 gm. of tryparsamide, 1 gm. of pentamidine and 24 doses of Eagle 70 A. After this treatment the CSF contained numerous trypanosomes and the patient was bedridden. A complete parasitological and clinical cure was then achieved by a two weeks treatment with eight injections totaling 1.44 gm. of Mel B, confirmed 4½ years after the treatment by normal CSF findings.