Purpose: To direct determination of rimantadine (RIM) with bromocresol purple (BCP) as a post column ultraviolet labeling reagent for use in HPLC with ultraviolet detection.Methods: Analysis is performed on an RP-18e column with methanol-acetonitrile-acetic acid (70∶30∶8 (v/v/v)) as mobile phase, was measured at 408 nm.Results: The mean intra-day precision was from 4.5% (low concentration) to 1.5% (high concentration) and within-day precision from 2.2 to 2.9 % determined on added samples.The accuracy of the method was 99.5-100.8%(intra-day) and 99.5-102.6% (within-day).Conclusion: The proposed methods have been applied successfully for the analysis of the drug in pure form and in its dosage form.