A significant change in the teaching strategies is required to improve the student's overall performance and the subjects' standards. Education research suggests that whole-brain teaching is a strategy that encourages students' motivation, involvement, attentiveness, and engagement in the classroom. The existing reviews also pointed out that more research studies have yet to be conducted in India among senior secondary students, particularly on Mathematics subjects concerning whole-brain teaching strategies. Therefore, the present study was planned to examine the effectiveness of whole-brain teaching on the academic achievement and self-concept of senior secondary school students in Mathematics. In 2022, a pre-test-post-test quasi-experimental single-group research design was adopted to complete this study. For conducting the present study, 25 students of the 11th class of Rajasthan Senior Secondary School Jalpali, Shrimadhopur Sikar (Rajasthan), India, were selected based on the low scores in the pre-test tests (achievement test & self-concept test in Mathematics). The experimental group was taught two units using a whole brain teaching strategy (key elements: attention getter, brain engager, direct instruction/ lesson chunks, mirror words, Motivation) as an intervention. After completing the intervention, post-tests were conducted. The data were analysed using a t-test, and the study results revealed that students' academic achievement and self-concept were higher in the post-test than in the pre-test. Therefore, the study's main findings were that WBT had a significant effect on the academic achievement and self-concept of senior secondary school students in mathematics. Therefore, it is suggested that teachers and policymakers support and implement whole-brain teaching into classroom practices. WBT should also be included in pre-service and in-service teacher education because it is an effective educational strategy that assists all students in meeting the subject standards as well as enhancing and succeeding them in a multicultural world. It can also be used as a high-energy, hyper-focused style in which teachers can employ games, challenges, keywords, and motivational strategies to keep students fully engaged in the learning. In the long run, this will be extremely useful to all levels of education.