Effectiveness and therapeutic value of the doxycycline plus streptomycin and doxycycline plus rifampin schedules of treatment of human brucellosis have been assessed by carrying out a prospective study on 111 patients randomly distributed into two groups. Patients in group A were treated with doxycycline plus streptomycin sulphate and those in group B with doxycycline plus rifampin. The temperature of all patients reverted to normal, and 54 patients from group A (91.6%) and 45 from group B (86.5%) achieved total recovery with a single therapeutic cycle. Two therapeutic failures and 3 relapses in group A (8.4%) and 7 relapses in group B (13.46%) were observed. The tolerance to both regimens was good. Although the combination doxycycline plus rifampin offers a more convenient oral administration, in the light of these results, until more extensive research is carried out, it should be considered as an alternative rather than a first choice in the treatment of human brucellosis.