The levels of flurithromycin in gynecological tissue in 20 female patients were studied after preoperative administration. The tissue flurithromycin levels obtained were comparable to those obtained in serum at 3 and 4 h but were frequently higher than those in serum at 6 and 12 h. Flurithromycin reached the highest concentrations in ovary at 4 h and in endometrium at 6 h.