This is a report of a randomized, open, labeled study of the maintenance treatment of melioidosis using a combination of ciprofloxacin and azithromycin (Regimen A) for 12 weeks versus a combination of cotrimoxazole and doxycycline (Regimen B) for 20 weeks. The study was conducted at two tertiary-care hospitals in northeast Thailand. A total 65 patients were enrolled, 36 and 29, respectively, between August 1997 and July 1998. Subjects were randomly allocated to each arm of the trial, resulting in 32 treated under Regimen A and 33 in B. The main outcome was a culture-proven relapse in melioidosis. There were more relapses under Regimen A at 22% (7 of 32) than in Regimen B, 3% (1 of 33). The 19% difference in the rates was significant (95% confidence interval [CI]: 3% to 34%; exact P-value = 0.027). Based on our data, a combination of cotrimoxazole and doxycycline treatment for 20 weeks should be given further consideration as the maintenance therapy of choice for melioidosis.