In common with other chronic illness, schizophrenia places a major economic burden on society, in terms of direct costs (in and outpatient care, residential care, drug therapy, etc.) and indirect costs (lost activity and earnings due to illness) and intangible costs (e.g. suffering experienced by the patient and family). Of the psychiatric illness, schizophrenia is by far the most costly: it develops early in life, results in high morbidity, is associated with a high suicide rate, and lacks a standard effective treatment. Analysis of worldwide epidemiological studies published during the last 30 years indicates that the prevalence of schizophrenia ranges from 0.6 to 9 cases per 1,000 population. The prevalence of treatment-resistant schizophrenia ranges from 5 to 30% patients. In other hand, clinical options for the management of treatment-resistant schizophrenia appears to be limited. Clozapine, an antipsychotic agent with relatively weak central antidopaminergic activity, displays atypical pharmacological and clinical properties towards the standard antipsychotics. Furthermore, clozapine is effective in a substantial proportion of patients who are refractory therapy. Although the acquisition cost of clozapine is high in comparison with that of standard antipsychotics, preliminary cost-effectiveness estimates in patients with treatment-resistant schizophrenia suggest that the clinical benefits of the drug (viz improved psychopathology; social functioning and quality of life) may confer medium to long term economic benefits, primarily by reducing the need for psychiatric hospital service.