Background: Premature birth is a source of severe stress for parents. In addition, preterm newborns are more likely to experience medical squeals and develop-mental delays. So the infant's optimal development outcome requires early intervention. Aim: To evaluate the effect of nursing intervention for Primiparous mothers regarding caring skills for their premature babies. Subjects and Methods: Design A quasi-experimental (pre-post-test) research design was used. Setting the study was applied at postpartum unit at Women's health Hospital, Assiut University. Subjects: A purposive sample of 100 primiparous mothers for pre and post-test. Two tools were used: Tool I, A structured interview questionnaire to collect data about mothers and their babies and tool II for mothers' knowledge regarding their caring skills.  Results: The findings illustrated that there highly statistically significant differences were detected between the mothers' knowledge regarding caring skills for their preterm babies in the pre and post-test which only 14 % of the studied mothers had good knowledge in pretest which increased significantly to 82% in posttest and most source of mothers from family and relative rather than health teams. Moreover, there was positive correlation between mother's age, educational level and occupation with total knowledge. Conclusion: The current study's findings concluded that nursing interventions increased primiparous mothers' knowledge about how to care for their preterm babies in a positive way, with a positive correlation between their overall knowledge in the pre- and post-test and the most effective variables that influenced mothers' knowledge were their educational level, age, and occupation. Recommendations: Educational programs for primiparous mothers about caring for their preterm infants should be included in clinical routine care.