Background: Otitis media is one of the most common childhood infections in pre-school aged children and a major cause of childhood morbidity. This study aimed toevaluate the effect of nursing intervention for improving mothers' care regarding their preschool children with otitis media. Research design: A quasi-experimental design was used. Setting: The study was conducted at the outpatient hearing clinic of Benha Specialized Children Hospital. The sample: A simple random sample was used, it included 100 preschool children. Two tools were used I: A structured interviewing questionnaire to assess; a) socio-demographic characteristics of the studied mothers and preschool children, b) medical history of preschool children, c) mothers' knowledge regarding Otitis Media, d) Mothers' reported practices regarding care of their preschool children with otitis media. II: Observational checklist to assess the practices of mothers on how to care for their children with Otitis Media. Results: More than half of the studied mothers aged 20 to less than 30 years, more than three fifths had university education,more than three fifths had good total knowledge while more than three quartershad satisfactory total practices. Conclusion: The nursing intervention succeeded in improving the studied mothers' knowledge and practices regarding care of their preschool children with otitis media.Recommendations: The study recommended availability of simplified and comprehensive Arabic booklet that deals with improving mothers' care knowledge regarding their preschool children suffering from otitis media and also further researches should be conducted for preschool children with other health problems.