BACKGROUND Measles is an infectious disease caused by Morbillivirus. Chinese physicians believe that medicinal herbs are effective in alleviating symptoms and preventing complications. Chinese herbal medicines are dispensed according to the particular symptoms. OBJECTIVE To assess the effectiveness and possible adverse events of Chinese medicinal herbs in treating measles. METHODS We searched the Cochrane Central Register of Controlled Clinical Trials (CENTRAL) (The Cochrane Library Issue 4, 2005); MEDLINE (1966 to June 2005); EMBASE (1980 to June 2005); the Chinese Biomedical Database (1976 to June 2005); VIP Information (1989 to June 2005); China National Knowledge Infrastructure (CNKI) (1994 to June 2005); and the metaRegister of Controlled Trials was searched for ongoing trials. METHODS Randomised controlled trials (RCTs) in which patients with measles without complications were treated with Chinese medicinal herbs were included. METHODS The primary outcome measure was death from any cause. The secondary outcome measure was improvement of overall symptoms. The tertiary outcome measure was fever clearance time. RESULTS We identified 28 trials which claimed to use random allocation. Nineteen study authors were contacted by telephone and we discovered that the allocation methods they had used were not actually randomised. Three studies were excluded because the patients experienced complications. We were unable to contact the remaining six authors. These require further assessment and have been allocated to the 'Studies awaiting assessment' section. CONCLUSIONS Two authors independently assessed trial quality and extracted data. We interviewed by telephone the study authors for missing information regarding random allocation of the study process. Some trials allocated the participants according to the sequence they were admitted to the trials, that is to say, by using a pseudo-random allocation method. None of the trials concealed the allocation or blinding method. We hope future randomised controlled trials (RCTs) in this field will be conducted.