Background: Parent's level of knowledge, state of their attitude, and their self-efficacy are the most incriminated reasons for the faulty application of the first aid measures, particularly in children's home injuries. Objectives: To assess the effect of a health education intervention on improving knowledge, attitude and self- efficacy of mothers having preschool children about home injuries and the basic first aid measures. Methods: A pre-posttest evaluation of the effect of a health education intervention on changing knowledge, attitude, and self-efficacy about home injuries and the basic first aid measures of 244 rural Egyptian mothers having preschool children. Results: About 35% of the male children had home injuries 8 weeks earlier to the study. Mean score of total knowledge increased from 10.21±3.1 in pretest to 18.90 ± 2.6 in posttest, total attitude from 6.19±1.8 to 10.26±2.3 and self-efficacy from 20.75±6.1 to 34.43 ± 10.1 with (p <0.001) for all changes. Age, education level and previous home injuries were the significant predicting factors for total knowledge, attitude and self- efficacy of the mothers. Conclusion: Health education improves knowledge, attitude, and self-efficacy of the mothers which were obvious regarding home injuries than first aid measures. There is a need for including knowledge about home injuries in the educational curriculum of high schools and universities and to perform training courses to mothers about first aid measures.