Background: Sleeping is necessary for the infant growth and development; So, mothers must follow recommendations of infant safe sleep to achieve the desired benefits from sleep and reduce sudden infant death syndrome. Aim: the study aimed to assess the mothers' knowledge and practices regarding infant safe sleep. Design: Descriptive correlational design was used. Setting: The study was conducted at outpatient pediatric clinicsaffiliated to Suez Canal University Hospitals and Ismailia Medical Complex at Ismailia City. Sample: none-probability Convenience sampling of 100 motherswith their infants who attended to the previous mentioned settings and agree to participate in the study. Tool: Structured interviewing questionnaire was used to assess the mothers' knowledge and reported practices regarding infant safe sleep. Results: The results of the study revealed that less than two thirds (63%) of studied mothers had unsatisfactory knowledge and reported practices regarding infant safe sleep, there were no statistically significant relationships among the studied mothers' characteristics and their total level of knowledge and reported practices regarding infant safe sleep. Conclusion: The study concluded that, the studied mothers had unsatisfactory knowledge and reported practices regarding infant safe sleep. However, there was a significant positive correlation between total knowledge and total reported practices. Recommendations: The study recommended that, educational programs about importance of infant safe sleep on infant's health should be organized for mothers; the contents of health education should include infant safe sleep guidelines.