OBJECTIVE: To study the clinical classification and characteristics as well as prognosis of mushroom poisoning. METHODS: We retrospectively analyzed 191 papers published domestically for 3466 cases of mushroom poisoning from 1995 to 2004 and studied the Xinqiao Hospital data of 172 cases of mushroom poisoning treated from 1980 through 2004. We made a retrospective investigation and clinical classification of all the 3638 cases of mushroom poisoning. RESULTS: Among the 3638 patients, clinical manifestations as gastroenteritis were found in 571, all of them were cured. The most common symptoms were those of acute renal failure being found in 1450 cases; 1414 were cases (97.5%) and 36 died (2.5%). Symptoms of toxic hepatitis were found in 1010 cases, 841 were cases (83.3%) and 169 died (16.7%). Psychoneurological disorder was manifested in 214 cases; 197 were cases (92.1%) and 17 died (7.9%). Erythrolysis was found in 73 cases; 71 were cases (97.3%) and 2 died (2.7%). The therapeutic effect and prognosis of mushroom poisoning with different clinical manifestation varied very significantly (P < 0.001). Of the 320 cases clinically unclassified, multiple organ dysfunction syndrome was found in 222 cases; 98 were cases (44.1%) and 124 died (55.9%). Definite classification could not be made in 98 cases; 90 were cases (91.8%) and 8 died (8.2%). CONCLUSIONS: The clinical classification of mushroom poisoning was usually of four types as described in the textbooks or special articles, but it should be of five types according to the analysis of the data of the present study, i.e. gastroenteritis type, acute renal failure type, toxic hepatitis type, psychoneurological disorder type and erythrolysis type. It is not clear whether there is a mixed type or not. Further investigation is needed in this respect.