BACKGROUND: Acute psychotic illnesses, especially when associated with agitated or violent behaviour, require urgent pharmacological tranquillisation or sedation. Clotiapine, a dibenzothiazepine neuroleptic, is being used for this purpose in several countries. OBJECTIVES: To estimate the effects of clotiapine when compared to other 'standard' or 'non-standard' treatments for acute psychotic illnesses in controlling disturbed behaviour and reducing psychotic symptoms. SEARCH STRATEGY: We updated previous searches by searching the Cochrane Schizophrenia Group Register (April 2004) SELECTION CRITERIA: The review included randomised clinical trials comparing clotiapine with any other treatment for people with acute psychotic illnesses. DATA COLLECTION AND ANALYSIS: Relevant studies were selected for inclusion, their quality was assessed and data extracted. Data were excluded where more than 50% of participants in any group were lost to follow up. For binary outcomes we calculated a standard estimation of the risk ratio (RR) and its 95% confidence interval (CI). For continuous outcomes, endpoint data were preferred to change data. Non-skewed data from valid scales were summated using a weighted mean difference (WMD). MAIN RESULTS: We identified five relevant trials. None compared clotiapine with placebo, but control drugs were either antipsychotics (chlorpromazine, perphenazine, trifluoperazine and zuclopenthixol acetate) or benzodiazepines (lorazepam).Versus the antipsychotics, the results for 'no important global improvement' did not suggest clotiapine to be superior, or inferior, to chlorpromazine, perphenazine, or trifluoperazine (n = 83, 3 RCTs, RR 0.82 CI 0.22 to 3.05, I-squared 58%). Use of clotiapine when compared with chlorpromazine did change the proportion of people ready for hospital discharge by the end of the study (n = 49, 1 RCT, RR 1.04 95%CI 0.96 to 2.12). Overall, attrition rates were low. No significant difference was found for those allocated to clotiapine compared with people randomised to other antipsychotics (n = 121, RR 2.26 95%CI 0.40 to 13). Weak data suggests that clotiapine may result in less need for antiparkinsonian treatment compared with zuclopenthixol acetate (n = 38, RR 0.43 95%CI 0.02 to 0.98). Compared with lorazepam, clotiapine, when used to control aggressive/violent outbursts for people already treated with haloperidol, did not significantly improve mental state (WMD -3.36 95%CI -8.09 to 1.37). We could not pool much data due to skew or inadequate presentation of results. Economic outcomes and satisfaction with care were not addressed. REVIEWERS' CONCLUSIONS: We found no evidence to support the use of clotiapine in preference to other 'standard' or 'non-standard' treatments for management of people with acute psychotic illness. All trials in this review have important methodological problems. We do not wish to discourage clinicians from using clotiapine in the psychiatric emergency, but well-designed, conducted and reported trials are needed to properly determine the efficacy of this drug.