This comprehensive review on puerperal infections covers risk factors, causative bacteria, pathophysiology, diagnosis, therapy of specific entities, and prevention. Puerperal infection is problematic to define especially with antibiotics that change the course of fever. I may present as endometritis (most common), myometritis, parametritis, pelvic abscess, salpingitis, septic pelvic thrombophlebitis or septicemia, and also includes infections of the urinary tract, episiotomy, surgical wounds, lacerations or breast. Each of these is discussed in terms of contributing factors, microbiology, clinical findings, diagnosis, treatment, prevention and complications. Risk factors in general are cesarean section, premature rupture of the membranes, internal fetal monitoring, general anesthesia, pelvic examinations. The most common bacterial involved are group B and other streptococci, E. coli, Gardnerella vaginalis, Gram positive anaerobic cocci, Mycoplasma and pre-existing Chlamydial infections. Diagnosis of the causative organism is difficult because of polyinfection and difficulty of getting a sterile endometrial swab. Diagnosis of the infection is equally difficult because of the wide variety of symptoms: fever, abnormal lochia, tachycardia, tenderness, mass and abnormal bowel sounds are common. Therapy depends of the responsible microorganism, although 3 empirical tactics are suggested while awaiting results of culture: 1) choose an antibiotic for the most common aerobic bacteria; 2) an antibiotic effective against B. fragilis and one for aerobic bacteria, e.g. clindamycin and an aminoglycoside; 3) a nontoxic antibiotic active against most aerobic and anaerobic organisms, e.g. doxycycline or cefoxitin. An example of an infection recently described is pudendal-paracervical block infection, often signaled by severe hip pain. It is associated with vaginal bacteria, is usually complicated by abscess even with antibiotic coverage, and may end in paraplegia or fatal sepsis. Prevention strategies are straightforward: handwashing, changing scrub clothes, isolation of infected patients, restriction of staff contact and prophylactic antibiotics for cesarean section patients at high risk, starting when the cord is clamped.