A simple, rapid, accurate and precise reverse phase-high performance liquid chromatographic (RP-HPLC) method has been developed and validated for the simultaneous determination of Terbutaline sulphate and Guaiphenesin in combined dosage form. Separation was performed using Phenomex C18 column (250*4.5 mm, 0.5 μ) on LC-20 AD Prominence Liquid chromatograph (Shimadzu, Japan) attached with Spd-20A/20AV Prominence SPD-20A prominence UV/Vis detector. By using mobile phase0.02 M Potassium dihydrogen orthophosphate (pH 3.0) and Acetonitrile (40:60 V/V) isocratic elution using a flow rate of 1mL/min. Good sensitivity was observed with UV detection at 215 nm. Retention times of Terbutaline sulphate and Guaiphenesin were found to be about 2.1 and 2.8 min, respectively. The method was validated over the range from 1.25-15 μg/mL for Terbutaline sulphateand 12.5- 150 μg/mL for Guaiphenesin with correlation coefficients of 0.998 and 0.998, respectively. This method was shown to be accurate, specific, robust, linear, and repeatable and can be successfully employed in routine quality control for the simultaneous analysis of Terbutaline sulphate and Guaiphenesin in tablets.