Introduction: To determine medical students' metacognitive awareness and its impact on their academic performance. Study design: Cross-sectional analytic study. Place and Duration of Study: Two different private medical College's from Lahore. From March 2016 to September 2016. Material and Methods: Study was done among second year students of two private medical colleges in Lahore. Students' first year academic achievement information was collected and they also filled the semi-structured questionnaire on metacognition regulation by the metacognitive awareness of reading strategies inventory (MARSI) based on three dimensions of metacognition (GLOB, SUB and PROB). Simple random sampling, a type of probability sampling was used for this study. The data were entered in SPSS 20, Metacognitive score was taken as an independent variable while academic performance (first professional part 1 results) was the dependent variable. For descriptive data, mean and standard deviation were used. For categorical data, percentage and frequencies were used. Pearson correlation coefficients were calculated to examine the item-total score correlation Result: A total 232 students participated. The reliability coefficient of MARSI was 0.88 and there was strong correlation among all dimensions of Metacognition score and academic achievement with Correlation coefficient value was 0.257 (p<0.01). Medical students of different colleges have almost equal (college 1 std. deviation 109±15.3, college 2 std. deviation 110.6±17.3) Metacognition levels. Conclusion: All dimensions of metacognition are positive and strongly correlated with each other's. Higher the score in one dimension will cause positive change in other dimension score and vice versa. Overall it would be beneficial for the trainers and other mentors that to work on one dimension and it would also cause positive impact on other skills and strategies.