Background: Antenatal care is a careful, systematic assessment and follow-up of pregnant women that includes education, counseling, screening, and treatment to assure the best possible health of the mother and fetus. Aim of the research was to examine the effect of antenatal instructional package on pregnant women' knowledge, attitude and practices. Design: A quasi-experimental research design was adopted to fulfil the aim of this research. Setting: The research was conducted at obstetrics & gynaecological outpatient clinic in Benha university hospital. Sample: A purposive sample of one hundred and forty pregnant women among those attending the above mentioned setting. Tools: Data were collected through five main tools: A Structured interviewing questionnaire, maternal knowledge questionnaire, maternal health attitude questionnaire, maternal health practices questionnaire, and women's satisfaction sheet. Results: showed that nearly one third of studied women in both study group (41.4%) and control group (37.1%) had source of information from friends and families while minority of them had source of information from newspaper. Also there was no statistical significant difference regarding all knowledge, attitude and practice items about antenatal care between the study and the control group before instructional package implementation. However, a highly statistically significant difference (p-values < 0.001) was observed between the study and the control group one month after instructional package implementation. Additionally total knowledge, total attitude and total practices regarding antenatal care were greatly improved after instructional package implementation than pre implementation among study group while there were minimal improvements after instructional package implementation than pre implementation among control group. Also the majority of pregnant women in the study group were satisfied with the antenatal instructional package implementation. Conclusion: the study concluded that research hypotheses are supported and the antenatal instructional package had appositive effect on improvement of pregnant women' knowledge and in turn attitude and practices were also improved in study group compared to control group .Also the majority of pregnant women in the study group were satisfied with the antenatal instructional package implementation. Recommendations: From time to time, the antenatal instructional package should be restructured and reviewed to meet up with the health needs of the pregnant women.