Academic Achievement is an effective means of assessing the extent to which students have mastered the concepts taught in a classroom. These tests are usually administered at the end of a teaching learning process to gauge the extent of learning that has taken place after a concept has been taught to the students. It is a means by which the success of a teaching program and the efficiency of the teacher and the process used can be measured. To ensure better academic performance, teachers need to use strategies that cater to differential student needs. Differentiated instruction is one such approach. Whether teachers differentiate content, process, products, or the learning environment, the use of ongoing assessment and flexible grouping makes this a successful approach to instruction. A research was conducted to study the Effect of Differentiated Instructional Strategies on the Academic Achievement of Higher Secondary School students. The paper throws light on the findings of the study and also highlights how differentiated instruction can help improve the academic achievement of diverse students in a classroom.