During 1988 and 1989 > 500 cases of serious group A streptococcal infections were reported in Sweden, many with a fatal outcome. We report here on 11 consecutive patients with septic preshock/shock and multiorgan failure, including acute renal failure. 10 had verified group A streptococci (GAS) serotype T1M1 infections while 1 patient was culture negative but with clinical signs of severe infection and serological evidence of GAS infection. Presenting symptoms were high fever, relative bradycardia, edema and renal failure. In all patients the condition deteriorated despite conventional treatment including volume substitution and antibiotics. Systolic blood pressure was transiently < 80 mmHg in 10 patients and 9 of them needed infusion of inotropic agents to avoid fatal circulatory shock. In 9 patients respiratory aid was instituted and 7 were dialysed. Plasma exchange was performed in 7, while the remaining 4 received transfusions with blood and plasma without plasma exchange. 10 patients improved and were discharged within 8 weeks. One woman died within 2 days after admission to the hospital. Renal function recovered in all survivors, with a follow-up serum creatinine < 80 mumol/l. The complicated clinical picture in these patients with many simultaneous therapeutic events confounds the interpretation of the effect of single actions. The favourable outcome in these severely ill patients suggests that potent inotropic agents, immunoglobulin therapy and plasma exchange might be beneficial in severe streptococcal disease when conventional treatment fails.