Background: Iron deficiency anemia in pregnancy is a major health problem and one of the leading causes responsible for maternal and perinatal morbidity and mortality. The aim of the present study was to investigate effect of health promotion instructions regarding iron deficiency anemia on young pregnant women's knowledge and practice. Subjects and Methods: Design: Aquasi-experimental design was utilized to fulfill the aim of the study. Sample: A purposive sample composed of 100 young pregnant women. Setting: The present study was conducted at two Maternal and Child Health Centers (Al Nahal Medical Center and Sheba MCH) affiliated with the Zagazig City Ministry of Health and Population. Tools of data collections: Data were collected by using five tools. Tool I: through an interviewing questionnaire form, Tool II: Pregnant women assessment sheet. Tool III: Assessment of women knowledge. Tool IV: Observation checklist and Tool VI Follow up record. Results: after implantation of health promotion instructions the mean hemoglobin level was increase among the study subjects in second and third trimester compared that in first trimester also there is a regress of signs and symptom of anemia in second and third trimester. As well as marked improvement of women total knowledge and practices towards IDA from 55% in pre to 83% in post and 80% in follow up of health promotion instructions. Conclusions: The present study concluded that the implementation of health promotion instructions improve young pregnant women’s dietary knowledge and practice thus it proved to be successful in raising the hemoglobin level. Recommendations: A nutrition education is recommended to enhance the nutritional knowledge of young mothers about iron rich foods, enhancer and inhibitors of iron absorption. Also should be provided with instructional booklets about anemia based on scientific background to improve their knowledge and health belief.