This study is a research piece that tries to examine and estimate the determinants of vertical intra industry trade of textile sector between Pakistan and its major trading partners. In the literature, along with many other variables, market size, income per capita and distance are considered to be the main and most important determinants of vertical intra industry trade. The current study adds to the debate by taking into consideration Pakistan’s textile industry and its intra industry trade. To achieve the goal of this study an augmented gravity model of international trade is developed and estimated. More specifically, product wise panel data for the time period 2003 to 2015 is used to estimate vertical intra industry trade of the textile sector in Pakistan. The system generalized method of moments augmented gravity model reveals that there is a much variation in the estimated results of Vertical Intra Industry Trade of the groups of textile industry. The behavior and significance level of a single variable varies across different groups of textile sector. For example, in case of silk group products market size and DGDPP have positive, GDPP, IPR and TI have negative and Dis, Tgap, Hgap, PR and Integ are insignificant Supervisor:- Dr. Usman Qadir