An epidemic of acute glomerulonephritis occurred in Israel during the summer and fall of 1968. A clear epidemiologic and etiologic correlation was found with a dominant type of hemolytic Group A streptococci, a newly identified serologic type in Israel. Its characteristics were found to correspond with those of type 55, a new type found in Trinidad. This type was isolated from cultures from both the throat and skin. A history of pyoderma was common. Antibiotic therapy of the antecedent infection apparently did not prevent the disease, nor did it affect the severity of the process. It did, however, eradicate the infecting organism and possibly affected the antibody response.