A precise and robust method was developed for simultaneous estimation of Acyclovir [ACY] and Dexamethasone [DEX]by RP-HPLC technique. The Method used Agilent 1260 Infinity II model HPLC with DAD detector and column of Agilent Zorbax Bonus RP with dimension 250 x 4.6 mm, 5 m. The Mobile phase employed was 0.1% Trifluoroacetic acid and Methanol using a gradient elution program. Flow rate at 1.0 ml/min and wavelength at 324 nm with run time of 10 minutes. The retention time of Acyclovir and Dexamethasone peakswas at2.34 minutes and 5.01 minutes, respectively. The method was validated as per ICH guidelines. The instrument precision, Method precision and Intermediate precision had %RSD of 0.09%, 0.11% and 0.10% respectively for ACY and 0.01%, 0.02% and 0.10% respectively for DEX. Method was linear for concentration range 0.025g/ml to 60g/ml with r2 of 0.9998for ACY and 0.025 g/ml to 60 g/ml with r2 of 0.9997 for DEX and accurate at 80%, 100% and 120% with % RSD for ACY of 0.07%, 0.09% and 0.07% and for DEX of 0.08%, 0.02% and 0.01%, respectively. Acyclovir and Dexamethasonewere studied for stress stability and found that ACY was susceptible to acid Hydrolysis with 11.71% degradation and Dexamethasone degraded in photolytic condition with 11.37% degradation. The established method can be used in commercial sense as it is very linear and the LOD and LOQ for ACY are very low as 0.41μg/ml and 1.25μg/ml and for DEX as low as 0.44 μg/ml and 1.33 μg/ml. The method was found to be robustness and precise.