Summary: This paper suggests a family of estimators of population mean using multi-auxiliary variate based on post-stratified sampling and its properties are studied under large sample approximation. An asymptotically optimal estimator in the class is identified along with its approximate variance formulae. The proposed class of estimators is also compared with the corresponding unstratified class of estimators based on estimated optimal value. At the end, an empirical study has been carried out to support the proposed methodology.