This study aims to examine the impact of instrinsic motivation and metacognitive awareness on students academic achievement. The study first tries to investigate whether there are any correlation between intrinsic motivation and  students academic achievement and also the correlation between metacognitive awareness and academic achievement. The study then goes to search whether intrinsic motivation and metacognitive awareness when they are combined together  have impact on student?s academic achievement. The sample of this study consist of 387 Senior High School students. The data collection is conducted with the use of Intrinsic Motivation Inventory (IMI), Metacognitive Awareness Inventory (MAI) and the students? grades. As a result, it was found that  intrinsic motivation has significant impact on the student?s academic achievement, meanwhile metacognitive awareness has no impact on students? academic achievement. But, intrinsic motivation and metacognitive awareness when they are combined together  gave 4% contribution to academic achievement.