Ten patients with brucellosis were treated with azithromycin and gentamicin to assess the treatment's safety and efficacy. Seven patients had an excellent therapeutic response at the end of therapy; however, relapse was noted in 3. When relapse was considered in combination with an initial lack of efficacy, 5 patients (50%; 95% confidence interval, 18.7%-81.3%) did not respond to therapy; these results do not favor the use of azithromycin to treat brucellosis in humans.