Twenty-nine patients, hospitalized in order to undergo gynaecological surgery involving organ removal, were treated with a single intramuscular administration of 1 g ceftriaxone before surgery. The tissue levels of the drug determined in the organs considered: uterus, ovary, fallopian tubes, vagina, proved to be comparable and to guarantee its satisfactory and uniform penetration into the tissues of the female genital system at a slowly decreasing rate. The high levels observed 12 h and 24 h after administration (2.24 +/- 0.74 mcg/g; 3.58 +/- 0.60 mcg/g; 0.70 +/- 0.45 mcg/g; 1.20 +/- 0.57 mcg/g in the ovaries and myometrium respectively) suggest a possible application of ceftriaxone in presurgical prophylaxis also in cases of female genital surgery.