In a ten-year review at a large community teaching hospital clostridia accounted for less than 1% of all positive bloodstream isolates (26 episodes in 25 patients). All but one of the isolates were clinically significant. Twenty-two patients (88%) had a serious underlying medical condition, and 17 of the episodes (65%) were associated with a bowel source; twelve patients (48%) died of their infection. Clostridial bloodstream infections are particularly clinically significant in patients with serious underlying disease.