The in vitro antibacterial activity of a new macrolide drug, flurithromycin, was evaluated in comparison with the activity of erythromycin A against some genital pathogens. The strains tested, C. trachomatis, U. urealyticum. M. hominis, N. gonorrhoeae, S. agalactiae and M. genitalium, were both clinically isolates and ATCC standards. The evidenced activity of flurithromycin is similar to that of erythromycin A. Resistances with both macrolides were found in all M. hominis strains and in one strain of U. urealyticum. No particular differences are exhibited between clinical and standard microorganisms.