Sensitive spectrophotometric method was developed for the determination of mirtazapine from pharmaceutical preparats. The proposed method was based on the formation of a yellow colored ion-pair complex by the reaction of methyl orange with mirtazapine. The ion pair complex was extracted with dichloromethane. Under the optimum condition, the ion pair complex showed an absorption maximum at 427 nm. The linearity range for concentrations of mirtazapine was found to be 2.5-12.5 mu g/mL. The proposed method is successfully applied to the determination of mirtazapine tablet formulations.