In a prospective study, 73 patients with erysipelas were studied bacteriologically, serologically and clinically. Pathogenic bacteria were isolated from 41% of the patients. Group G streptococci (GGS) were found as frequently as group A streptococci (GAS), in 12.5% and 15% of patients, respectively. Staphylococcus aureus was isolated in 10%, and streptococci groups B, C and D were isolated from one case each. Raised ASO titres were found among patients with GAS and GGS, while a rise in ADNase B titre was found only in patients with GAS. Patients with GGS tended to be older than other patients. Otherwise no clinical differences were noticed. The infection was located to the lower extremity in 68%. Predisposing factors were observed in 44% of the patients, predominantly local circulatory insufficiency and malignancies. In 55% a possible portal of entry was present. GGS seems to be a common cause of erysipelas, especially among patients older than 50 years.