A new, simple, precise, accurate and rapid RP- HPLC method has been developed for the simultaneous determination of Cephalexin and Carbocisteine from capsules, using 0.025 M monobasic sodium phosphate: acetonitrile (87:13, v/v) as a mobile phase, and a C8Shodex column as the stationary phase. Detection was carried out using a UV detector at 210 nm. The linearity range for Cephalexin and Carbocisteine were 50 - 300 μg/mL and 40 - 200 μg/mL, respectively. Assay values for Cephalexin and Carbocisteine were 99.46% (R.S.D. - 1.30%) and 99.22% (R.S.D.-1.34%) for Brand 1. and 99.71% (R.S.D. - 1.68%) and 99.43% (R.S.D. - 1.78%) for Brand 2, respectively.