The aim of the study was to evaluate the effect of occupational health program for nurses on reducing musculoskeletal injuries- to evaluate the effect of occupational health program on nurse's knowledge and performance of body mechanics. Abstract: nurses require application of the body mechanics principle to avoid physical harm decreases the risk of damage to the body, fatigue, and increase practice satisfaction Design: A quasi-experimental study design. Setting: The present study was carried out in the Physical Medicine and Rehabilitation Center affiliated to the Military Army force, in Al Helmia district, in Cairo governorate. Sample: all nurses in the Rehabilitation Center with total number of 30 nurses. Tools: two tools were used for data collected: First tool: Questionnaire Sheet: to collect data about Socio-demographic characteristics of the studied nurses - To assess nurse's knowledge Pre-post program implementation regarding Body Mechanics principles and musculoskeletal health hazards. To assess nurse's pre-post musculoskeletal pain. Second tool Observational Checklist: to assess nurses' performance of Body mechanics pre -post program. Results: The findings of the study clarified that, Nurses' performance of Body Mechanics improved after application of the program about proper body mechanics in the performance of standing and setting with statistical significance and improved in lifting technique with no statistical significance. Conclusion: The findings of this study provide that, some of the nurses did not performed techniques of body mechanics correctly. Nurses' body mechanics improved after application of occupational health program about proper body mechanics. There is a no statistical relation between nurse's knowledge and performance of body mechanics. There is an improvement in nurse's musculoskeletal compliance regarding pain after program implementation with no statistical significance. Recommendations: It is suggested that: 1- Creation of continuous, planned and efficient in-service occupational health programs for nurses on body mechanics. 2-Enough supply the health facilities of patient-lifting devices which have been shown to be effective in decreasing costs and workdays lost to back injuries and pain among nurses.