Back pain is common, with about nine out of ten adults experiencing it at some point in their life, and five out of ten working adults having it every year. The occurrence of low back pain in India is also alarming with nearly 60% of the people in India have suffered from low back pain at some point of time during their lifespan. It is the most common cause of chronic pain, and is a major contributor of missed work and disability. Low back pain can interfere with daily activities, but Back Strengthening Exercises may reduce low back pain and increase in physical activities. The objective of this study was to determine the effectiveness of back strengthening exercises on low back pain among school teachers in Kanyakumari District, Tamil Nadu. A quantitative approach with quasi experimental; one group of pretestposttest design was used. Thirty school teachers were selected by using purposive sampling technique. Pre-test was conducted and then taught about Back Strengthening Exercises with the help of pamphlet. Post-test assessment was done in one month after intervention. The findings showed that the pre-test mean pain score of Back Strengthening Exercises was 3±0.8 and after post-test was 1.4±0.5. The mean reduction of pain was 1.6±0.8. It was statistically highly significant at P<0.001 level. The present study also supports the necessity for doing exercises regularly that helps to reduce low back pain among school teachers.