A simple, efficient and reproducible Reverse Phase-High Performance Liquid Chromatography (RP-HPLC) method for simultaneous estimation of Ambroxol hydrochloride, Cetirizine hydrochloride, Methylparaben and Propylparaben in combined liquid pharmaceutical formulation has been developed. The separation was carried out on Hypersil BDS C18 (200x 4.6mm i.d., 5μm) column using acetonitrile: 0.05 M potassium dihydrogen orthophosphate (adjusted to pH 3.5 with ortho phosphoric acid) in the ratio of 33:67 v/v as eluent. The flow rate was 1 ml/min and effluent was detected at 230 nm. The retention times of ambroxol hydrochloride, cetirizine hydrochloride, methylparaben and propylparaben were 3.97 min, 15.30 min, 5.74 min, and 17.54 min, respectively. The percentage recovery was within the range between 98.36% and 99.96% for ambroxol hydrochloride, 100.00% and 101.49% for cetirizine hydrochloride, 99.58% and 100.40% for methylparaben and 100.00% and 101.82% for propylparaben. The linear ranges were found to be 192-288μg/ml (r2 = 0.9970) for ambroxol hydrochloride, 16- 24μg/ml (r2 = 0.9957) for cetirizine hydrochloride, 64-96μg/ml (r2 = 0.9961) for methylparaben and 6.4-9.6μg/ml (r2 = 0.9915) for propylparaben. The percentage relative standard deviation for accuracy and precision were found to be less than 2%. Hence, the method could be successfully applied for routine analysis of ambroxol hydrochloride, cetirizine hydrochloride, methylparaben and propylparaben in combined liquid dosage form.