Background: Occupational health hazards in agricultural work are subjects to the health and safety risks inherent to a rural environment and deriving from the specific work processes. Aim: Evaluate the effect of occupational safety program regarding preventive measures of occupational health hazards among agriculture child labor. Design: A quasi-experimental design was used.Settings: - Cluster sample was conducted in Kafr Shokr sector in Qalyubia Gover, it includes 23 Village, 25% was selected from 23 Village, 5 Village was selected, 5 Preparatory School was selected then followed by visits. Sample: Simple random sample. Tools: Two tools were used; Tool (I): A structured interviewing questionnaire: Which included; Socio-demographic characteristics of the studied children and children`s parents' data, occupational data of studied children and work environmental condition, history of occupational health problems and knowledge of children regarding occupational health hazards and first aid instructions. Tool (II): Observational checklist. That divided to; use of protective equipment, child practices regarding preventive measures of occupational health hazards.Results: 7.6% of children had good total knowledge level regarding occupational health hazards of agriculture labor that improved to be 70.5% of them post occupational safety program implementation,89.4% of them had satisfactory total practices level regarding using protective equipment post occupational safety program implementation . Conclusion: Occupational safety program regarding preventive measure had succeeded in improving the children knowledge and practices regarding occupational health hazards at agriculture labor. Recommendations: Develop continuous safety program about protective measures for all children at work place to prevent occupational health hazards.