A study is presented on the incidence and complications of septic abortion in a group of patients admited on the 1st. Obstetric and Gynecologic Clinic of the University of Barcelona during a period of 5 years (1971-1975). Abortion is the cause of admision of 20,2% of patients in the gynecology ward and represents the 12,3% of the overall number of patients during the same period. In 7,8% of the patients admited because of abortion we found the criteria for establishing the diagnosis of septic complication and in 15,2% of those extrapelvic involvement is found, mainly endotoxic shock, acute renal failure and difuse peritonitis. Endocervical cultures were positive in 73% of cases and in 65,7% gram negative germs were isolated, being the most common E. coli. The different clinical patterns are discussed in cases in which anaerobics are implicated and the diagnostic and therapeutic aproaches in the different complications are reviewed particularly in concern to the indications of surgery when this may be the only lifesaving procedure.