87 beta-haemolytic streptococcal septicaemias in adult patients during 1979-86 in a university hospital were reviewed. 25% were caused by group A streptococcus, 17% by group B, 14% by group C and 44% by group G streptococcus. 67% of the septicaemias due to group B streptococcus were nosocomial, whereas the group A, C or G septicaemias were in most cases community-acquired. Alcoholism was the most common underlying disease in group A (32%) and malignancy in group G streptococcal septicaemias (45%). The most common origin and focus of infection in group A, C and G streptococcal septicaemias was the skin. The total mortality in beta-haemolytic streptococcal septicaemias was 20%, higher in septicaemias caused by group A (32%) and group B (33%) than by group C (17%) and group G (8%) streptococci. Nevertheless, there were more patients in group G streptococcal septicaemias with severe underlying diseases than in other groups of beta-haemolytic streptococci. The present data seem to indicate that a septicaemia due to group G is a more benign disease than a septicaemia due to group A streptococcus.