High quality antenatal care is a fundamental right for women to safeguard their health. Furthermore, obstetric care of high quality continues to be a key requirement for reducing maternal mortality. There is a very urgent need to focus on the antenatal period for both the mother and newborn., Aim: To evaluate the impact of protocol of care on quality of nursing performance in antenatal unit., Design: A pre-post intervention study design was used., Setting:The antenatal unit in obstetrics ward at Benha University Hospital. Sampling: A total of 40 nurses and purposive sample of 120 pregnant women were recruited in the study) , Tools of data collection: Four types of tools were used for data collections which include Part 1: Interviewing questionnaire schedule sheet. Part a: Socio demographic data for nurses ,Part b: Socio demographic & obstetrical data for women, Part II: Questions were used to assess nurse's knowledge about antenatal care 2-An Observation check list was used to assess the quality of nursing performance in antenatal unit based on standardized nursing care model during antenatal period 3-Two points likert scale to monitor women satisfaction with the components of antenatal care received 4- A protocol of care regarding antenatal nursing care to be implemented in the form of teaching and training sessions in order to improve nurses’ performance., Results: Significant differences regarding nurses mean scores of knowledge and performance before, immediately after, and 3 months later after the implementation of the interventions regarding most of the studied items , Also lack of equipment and supplies and prolonged waiting time in antenatal unit, Conclusion: It can be concluded that the majority of nurses lacked the essential knowledge regarding antenatal care and the quality of nursing performance provided for women at the antenatal unit. Also, about two third of women before implementation of the interventions were less satisfied with many of the studied items of the quality of nursing performance .While after conducting of the interventions immediately and follow up three months, most of women were generally satisfied with the quality of care provided to them. There were also obvious changes in the infection control precautions regarding performing many of antenatal care procedures. , Recommendation: The study recommended assertive and continuous supervision of nurses’ performance must be applied to antenatal units, also in-services training programs and continuing training courses regarding antenatal care for nurses should be applied and provided periodically.