Bacteremia with Peptococcaceae is an uncommon clinical manifestation of infection with this family of microorganisms. A 20-month review of 12 patients with bacteremic infections due to anaerobic gram-positive cocci revealed that obstetrical patients during the peripartum period constitute the group at greatest risk for the development of such infections. Eight of the 12 patients were young women hospitalized on the obstetrical service. Seven patients had postpartum endometritis and one patient had chorioamnionitis. The remaining four patients include a single patient each with pylephlebitis and microabscesses of the liver, ascending cholangitis, thoracic empyema, and necrotizing soft-tissue infection. Bacteriologic identification of the microorganisms revealed the following: Peptostreptococcus micros (5 patients), Peptostreptococcus asaccharolyticus (5 patients), Peptostreptococcus magnus (1 patient), and Peptococcus species (1 patient). Eleven of the 12 patients received appropriate antibiotic therapy. All patients did well and there were no major sequelae.