Background: Assessment of fetal well-being during pregnancy is a critical tool for ensuring optimal neonatal outcomes. Nurses have a major role for assessment of fetal wellbeing and improving the physical and psychosocial maternal condition. Aim of the study: Was to evaluate the effect of instructional package on maternity nurses' knowledge and practices regarding assessment of fetal wellbeing. Study design: A quasi-experimental design was utilized. Setting: The current study was conducted at Obstetrics and Gynecological department affiliated to Benha University Hospital. Sample: A convenient sample included 50 maternity nurses. Tools of data collection: Two tools were used for data collection and included: Tool (I) Part I Self-administered questionnaire to assess maternity nurses' demographic data. Part II Assessment of maternity nurses' knowledge regarding assessment of fetal wellbeing. Tool (II) Observational checklist was used to assess maternity nurses' practices regarding assessment of fetal wellbeing. Results: The result of present study revealed that there was a highly statistically significant difference in relation to total nurses' knowledge and practices about assessment of fetal well-being pre, post and at follow up phases of instructional package implementation. Moreover, there was a positive statistically significant correlation between total knowledge and total practice scores pre, post and at follow up phases of instructional package implementation. Conclusion: The instructional package had a positive effect on improving knowledge and practices of maternity nurses regarding assessment of fetal wellbeing. Recommendations: Develop periodic in-service training programs for nurses to enhance their practical skills regarding assessment of fetal wellbeing.