In this paper we consider a two parameter ratio-product-ratio estimator for estimating population mean in case of post stratification following the estimator due to Chami et al (2012). The bias and mean squared error of proposed estimator are obtained to the first degree of approximation. We derive conditions under which the proposed estimator has smaller mean squared error than the sample mean y ps , ratio estimator yR( ps) and product estimators yP( ps) . Empirical studies gives insight on the magnitude of the efficiency of the estimator developed.