The authors discuss the present value of rifampicin in the treatment of human brucellosis on the basis of: 1) a bacteriological study of 42 strains of Brucella spp. (MIC's of rifampicin, tetracyclin, doxycyclin, minocyclin and streptomycin; results of doxycyclin-rifampicin and doxycyclin-streptomycin combinations), and 2) a clinical study of 38 cases of brucellosis treated with rifampicin, including 25 acute septicemias and 13 osteo-arthritis. Satisfactory results were observed in 92% of the cases with rifampicin alone, but one cannot state that the benefits are significant.