The high prevalence of hypertension and associated risk factors among school children indicate that hypertension is not restricted to older age but stems in childhood itself. Cognition related to the disease is a primary step in warranting its manifestation. Hence, this study aims to explore the efficacy of a 30-minute audio-visual hypertension knowledge intervention facilitated by a health psychologist in increasing awareness about hypertension; the retention of information, and its effect on healthy lifestyle practices among children. A sample of 100 children was recruited through purposive sampling and was assessed using the Hypertension Knowledge Test (HKT) and Healthy lifestyle Practice Scale for Children and Adolescents (HELIPSCA). Post assessing the baseline scores for HKT and HELPISCA,the children were re-administered HKT immediately after the first exposure, the second exposure (after two weeks), then after 6 weeks of first exposure, and followed up after an interval of 10 months along with a post-test administration of HELIPSCA. Results were statistically tested using paired t-tests which revealed a significant improvement in hypertension knowledge levels among the children. However, there was no significant change in the self-reported lifestyle practices of the children. This school-based knowledge intervention holds promise as an innovative method to raise school children’s knowledge about hypertension through video-based educational intervention.