A cluster of four group A (β-hemolytic Streptococcus postoperative wound infections was investigated at a community hospital. The serotypes of the Streptococcus isolated from all four cases, an asymptomatic anesthesiologist and one of his household members were M nontypable T28. During the outbreak period, December 1988, the infection rate among the 40 patients of the anesthesiologist was 7.5%. Among other patients not having contact with this healthcare worker, it was 0.09% (p = .0002 Fisher's exact test). This is only the second reported Group A β-hemolytic Streptococcus hospital outbreak in which the pathogen was traced to a member of a healthcare worker's household. Early outbreak detection and intervention limited the extent of the outbreak.