A total of 186 patients who met the DSM-III criteria for schizophrenia were admitted to a double-blind randomized multicentre trial in which the efficacy and safety of remoxipride at two dose levels was compared with those of haloperidol. Over a period of six weeks the patients received remoxipride 100-300 mg/day (n = 60), remoxipride 200-600 mg/day (n = 61), or haloperidol 10-30 mg/day (n = 64). There was no significant difference between the three treated groups with regard to the Brief Psychiatric Rating Scale (BPRS) and Clinical Global Impression (CGI) scores obtained. Remoxipride, at both dosage ranges used, thus had comparable therapeutic efficacy to that of haloperidol. In contrast, extrapyramidal symptoms occurred significantly more frequently in the group treated with haloperidol. Laboratory tests and cardiovascular investigations showed no specific drug effect in any of the treated patients. Remoxipride is thus effective in acute treatment of schizophrenia at both dosage levels and has an advantage over haloperidol in neurological acceptability.