Group F streptococci are part of the oropharyngeal, bowel, and perineal flora. Abscess formation by these organisms most commonly involves the cutaneous system: the next most common sites, in descending order, are the cervicofacial, dental, and intraabdominal areas. Among our population of patients with abscesses, serious infection rarely occurred in otherwise healthy individuals in the absence of trauma. Group F streptococci represented 2% of beta-hemolytic streptococcal isolates from all patients with bacteremia who were hospitalized at Mayo Clinic-affiliated hospitals from 1970 to 1980. In five of seven bacteremic patients, some manipulation, perforation, or underlying pathology associated with the gastrointestinal tract existed. Polymicrobial bacteremia was common. All isolates of group F streptococci were susceptible to less than or equal to 0.1 microgram of penicillin/ml.