Bakery workers face many hazards in their work environment, and these hazards may cause injury or illness. The aim of this study was to assess the effect of educational intervention on knowledge and practices of bakery workers about first aid related to occupational hazards. A quasi-experimental design was used. Simple random samples composed of One hundred and eleven bakeries were recruited in Zagazig City. Two tools were used: Tool (I): Demographic characteristics, job characteristics of bakers, job exposures and related signs/symptoms, and knowledge of first aid among bakers. Tool II. Bakers practice observation checklist about first aid and ergonomic maneuvers, and work environment safety of the bakeries. Results: The greatest hazard related to job exposure was physical (53.2%) followed by psychological stress (36.9%). The major health problems reported by bakers were headache (65.8%), bone aches (54.1%) followed by arrhythmia (45.9%), and dry cough (45%). The total satisfactory score of knowledge increased from 16.2% in pre intervention to 100% at post intervention, only 0.9% of the bakery workers had total adequate practices about first aids before intervention compared with 75.7% with significant difference between scores of before and post- intervention at p<0.001. Conclusion: An improvement was noticed between the bakery workers before and after intervention implementation related to their knowledge and practices of all first aid items and ergonomic maneuvers. Recommendation: Continuous educational intervention should be initiated for all workers of bakeries in Sharkia Governorate to raise their knowledge and practices about first aid, and ergonomic maneuvers.