Background: Children under five years aren't only constitute a large group but also they are vulnerable or high risk group for communicable diseases. Pneumonia and diarrhea are the leading causes of death among them around the world. Aim: This study aimed to assess the nursing performance related to prevention of communicable disease among children under five years Research design: Descriptive research design was used in the study. Setting: The study was conducted at the maternal and child health care centers and primary health care units in Banha and Toukh health directorate at Qalyubia governorate. Sample: Multistage random sampling technique was used (116 nurses) .Tools of data collection: Two tools was used in the study. First Tool: Self-administered questionnaire to assess socio-demographic characteristics and knowledge of nurses and the factors affecting community health nurses' performance Second Tool: 6 observational checklists about vaccination, hand washing, intradermal, intramuscular, subcutaneous, health education procedure. Results: There were more than three quarters of nurses were graduated of technical secondary school, more than half of them had unsatisfactory knowledge, and the majority of  them had inadequate level of performance, There was significant statistical relation between total knowledge of nurses and their educational level, There was a highly significant relation between total nurses' knowledge and their total performance, all of nurses mentioned that the factors affecting nursing performance were lack of an equipped room to conduct health education sessions for mothers and lack of infection control supplies. While most of them said that, there is no support and motivation for nurses to encourage them to work. Conclusion: Presence of a strong negative statistically significant correlation between the total scores of nurse's performance and factors affecting their performance related to lack of mother's response to health education about modifying bad health habits. Recommendation: Continuous supervision and evaluation for nurses concerned with child health care is required to determine the defect related to their knowledge or practice.