31 patients suffering from puerperal endometritis, 16 of whom with other concomitant infections (sepsis, infection of episiotomy, pyelonephritis) were treated with fosfomycin. 86% of the germs isolated were sensitive to fosfomycin. The results obtained have been excellent in 26 patients (84%) and null in 5 (16%). Fosfomycin showed to be an antibiotic of wide-spectrum, and it acted very rapidly, since apirexia of the patients was achieved after 2–3 days of treatment. The antibiotic had perfect tolerance. No disagreable secondary effects nor changes in the haematological data were observed. We have also carried out a study on the elimination in lochia of fosfomycin in a group of 21 patients with normal birth and puerperium. The concentrations of the antibiotic in lochia, although variable, are sufficient to achieve the desired bactericide actio