Context: The school age children face daily responsibility of carrying variety of items to and fro and also around school. "Back pain" is currently emerging as a major health problem among school age group children, which can limit their daily activities. Aim: The aim was to investigate the factors that reflect the prevalence of back pain among school age group children, with particular attention on the weight of backpacks′ mode of transportation to school. Materials and Methods: A total of 626 children are registered for this study between the age group of 12-16 years. They are weighed twice on the digital scale; the first time with their backpacks on and the second time without any backpacks. Questionnaire made and used to determine the presence and severity of back pain; data analyzed and descriptive statistics and multimonial regression analysis are performed to investigate the reflection of certain factors like gender, school bag carrying method, bag weight to student weight ratio, mode of transportation etc. on the occurrence of back pain. Odds ratio (OR) obtained from the analysis are used to compare the different levels of the same factor for relative occurrence of back pain. Results: Of 626 students; 172 are female, and 454 are male; 318 (50.7%) carried backpacks weighing 10-15% of their body weight. Among 626 students, 358 (57.1%) are reported to have back pain, 12.6% students required physician′s visit and 18.6% students missed school because of back pain. Students carrying more than 15% of their body weight are found to have higher risk of back pain with (odds ratio = 4.3459 confidence interval = 95% 2.63-7.169, P = 0.0001). 425 students are reported to have walked to school with their backpacks on, out of which 260 (61.17%) are reported with back pain; significant association with P = 0.0004 is found among these subjects who walked to school with their back packs on. Conclusion: Carrying heavy backpacks increases the relative risk of back pain among school age group children, and prevalence of these children are found to be extremely high. Therefore, preventive and educational activities must be implemented among these school age group children.