PURPOSE: The purposes of this study were to investigate extent of backpack use and incidence of musculoskeletal pain, and to identify the relationship between backpack use and musculoskeletal pain. METHOD: A descriptive correlational study was conducted in one elementary school and one middle school in D city. Participants were 273 children, aged 12-14, who completed a self-administered questionnaire. Body weight, height, and backpack weight of participants were measured. RESULTS: Mean backpack weight was 3.78 Kg and relative backpack weight (RBW) was 7.42%. Of backpack users, 23.8% carried more than 10% of their RBW and 9.2% carried more than 15%. Only 44.3% organized the contents in their backpack correctly. For more than three fourth of the students (76.2%), the bottom of backpack in the standing position drooped more than 10 cm below the waistline, and 46.3% complained of musculoskeletal pain. Use of a waist belt was significantly related to musculoskeletal pain. CONCLUSIONS: A considerable proportion of school children were not following guidelines for safe backpack use. Although the relationship between backpack use and musculoskeletal pain in this study was not significant, the fact that 46.3% of the students experienced musculoskeletal pain is very meaningful information. Further research is required to identify the risk factors of musculoskeletal pain among children.