ObjectiveTo determine the prevalence of Mycobacterium tuberculosis resistance to antituberculosis drugs, and to relate this resistance to HIV serologic status. DesignCross-sectional prevalence study. SettingThe two major outpatient tuberculosis clinics in Abidjan, Côte d'Ivoire, West Africa. PatientsSixty individuals with newly diagnosed pulmonary tuberculosis and sputum smears positive for acid-fast bacilli. Main outcome measuresHIV serologic status and in vitro testing for susceptibility of M. tuberculosis isolates to antituberculosis drugs. ResultsM. tuberculosis was isolated from 82% (49 out of 60) of sputum specimens. Thirty-five per cent (17 out of 49) were obtained from HIV-seropositive and 65% (32 out of 49) from HIV-seronegative patients. There was no statistically significant difference in the proportion of resistant isolates from HIV-seropositive versus HIV-seronegative patients, although the relatively small sample size limited power. Of the total number of isolates, 17% were resistant to isoniazid; resistance was less to streptomycin (7%), rifampin (2%), pyrazinamide (0%), and ethambutol (0%). Eighteen and 21% of mycobacterial isolates from HIV-seropositive and HIV-seronegative individuals, respectively, were resistant to one or more of these drugs. ConclusionsSurveys of this type are useful in planning and evaluating tuberculosis preventive therapy in individuals with dual infection.