Iloperidone is an antipsychotic drug used for treatment of acute schizophrenia in adults. In this study, a simple and specific method was developed for determination of iloperidone in tablets. The separation was performed on a C18 column using pH 3 20 mM phosphate buffer and acetonitrile as the mobile phase. The optimum conditions were 1 ml/min flow rate, 35 degrees C column temperature, and 2 mu L injection volume. Carbamazepine was used as an internal standard. Iloperidone was monitored at 274 nm with a diode array detector. The method was validated according to the literature guidelines and was linear from 0.5 to 100 mu g/ml of iloperidone. The detection and quantification limits were 0.0909 and 0.3030 mu g/ml, respectively. The method was acceptable in terms of accuracy, precision, specificity, robustness, and stability and employed for the analysis of tablets.