To estimate the potential efficacy of telithromycin in the treatment of gynecological infections, a pharmacokinetic study was conducted in 13 Japanese subjects. Telithromycin was administered orally, at a dose of 600mg, to patients undergoing hysterectomy, 3.0 to 7.5h prior to the hysterectomy. At surgical operation, cubital venous blood, uterine arterial blood, vaginal cervix uteri (portio vaginalis), supravaginal uterine cervix, uterine endometrium, uterine myometrium, oviduct, and ovary specimens were collected separately. The blood and tissue concentrations of telithromycin were measured with a bioassay, using Micrococcus luteus ATCC 9361 as the test organism. The concentrations of telithromycin in these tissues and their proportions in relation to that in cubital venous blood (in parentheses) were as follows: cubital venous blood, 0.119 to 1.270mg/l; uterine arterial blood, 0.111 to 1.230mg/l; vaginal cervix uteri (portio vaginalis), 0.356 to 1.850mg/kg (1.324 to 5.640), supravaginal uterine cervix, 0.376 to 4.520mg/kg (1.108 to 16.807), uterine endometrium, 0.234 to 5.300mg/kg (0.975 to 12.185), uterine myometrium, 0.309 to 5.050mg/kg (1.288 to 19.832), oviduct, 0.375 to 5.550mg/kg (1.563 to 10.000); and ovary, 0.495 to 5.250mg/kg (1.835 to 6.851). From these results, it was concluded that the concentrations of telithromycin in female genital tissues are generally higher than those in blood. Taking the antimicrobial spectrum of telithromycin into consideration, it was suggested that telithromycin could potentially be a good candidate for the treatment of gynecological infections, including cases associated with sexually transmitted diseases.