Selection of appropriate language of instruction has remained the point of discussion for the policy makers since 1st education policy of Pakistan. Pakistan is a multilingual country due to which various provincial / regional languages are spoken therefore, medium of instruction at national level has ever been remained questionable in the country. It seems obvious to many educationists that learners learn best through a language they understand well, there is also considerable support for retaining the English as medium of instruction in Pakistan.. The main objective of this study was to explore the impact of English as medium of instruction on student learning at primary level in Lahore. A descriptive method of research was used for the collection of data. Out of all the population of teachers of Lahore Cantt, 80 teachers were selected from 8 schools by systematic random sampling technique. An adapted questionnaire having 30 statements as research instruments was used to collect the data. Data was analyzed in SPSS software. Various formulas i.e., mean score, percentage, standard deviation, and mode for each statement was used. Appropriate recommendations were made in light of the findings.