The Etest was used for antibiotic susceptibility testing of Mycoplasma hominis and Ureaplasma urealyticum isolates and the results were compared with those obtained with the broth microdilution method. For 50 clinical isolates of M. hominis the MICs of doxycycline, ofloxacin and ciprofloxacin agreed within +/- one dilution and +/- two dilutions in 82-98% and 98-100% of cases, respectively. The MICs of erythromycin, azithromycin, doxycycline, ofloxacin and ciprofloxacin were evaluated for 50 clinical isolates of U. urealyticum. The corresponding levels of agreement were 70-98% and 94-100%, respectively. Reference isolates M. hominis PG-21 and U. urealyticum T-960 were also used. The Etest seems to be an alternative method for determination of MICs of antibiotics with M. hominis and U. urealyticum.