205 cases of clinical poisoning with the mushroom Amanita phalloides (death cap) in the period 1971 to 1980 have been studied retrospectively. The lethality was 22.4%. Age and latency between the ingestion of the mushrooms and the first clinical symptoms were of prognostic significance. The death rate was 51.3% in children below 10 years of age but only 16.5% in patients older than 10 years. The average latency period was 10.3 hours for the fatal cases and 12.6 hours for the surviving patients. Country, year, sex and time of hospitalization did not influence lethality. Prognostic relevance could also be attributed to the thromboplastin time (Quick). 84% of the patients with values below 10% died, while all patients with minimal values of more than 40% survived. The correlation with the outcome was weaker for the serum transaminases and nil for creatinine. The patients underwent on the average 8 therapeutic measures, but up to 20 therapies could be administered to the same patient. Eight of the 30 recorded treatments involved general support, 7 toxin elimination and the remaining 14 could be classified as pharmacotherapy. With the aid of multiple regression analysis taking into account age, latency period and the effects of all the other measures, penicillin and hyperbaric oxygenation were found to contribute independently to a higher survival rate. As compared to penicillin, the combination of penicillin with silybin was associated with still further increased survival. On the other hand, several measures, including exchange transfusion, thiocytic acid, sulfamethoxazole, plasma expanders, haemodialysis, treatment of the hemorrhagic diathesis and THAM/sodium bicarbonate were administered more often to patients who did not survive. For the remaining 20 therapeutic measures our analysis revealed neither a positive nor a negative correlation with the clinical outcome.