Introduction: Primary health care (PHC) facilities are widely distributed throughout Egypt but they often seem to operate at suboptimal level. Therefore this study was carried out in a trial to increase the rate of utilization of PHC in rural sector of Sharkia Governorate using a social marketing campaign. Objectives of study: To assess the rate of utilization of child PHC services in rural sector of Sharkia Governorate, to determine causes of underutilization and to assesss the effect of social marketing campaign on utilization of health services. Method: Design: Pre- Post interventional study. Setting: El-Sharkia Governorate, Hehya district, El-Shabraween village. Sampling: multi-stage random sampling. Procedure: the study evaluated the utilization of all provided PHC services in El-Shabraween unit before and after a social marketing campaign using personal interviews of 205 households and the unit records. It also highlighted the causes of underutilization of the PHC unit. Results: There is a significant increase in El-Shabraween outpatient consumers from 23% before to 58.8% after the campaign. The percent proportion of recorded diarrhea cases among (U5) children to total U5 sick children increased from 35.1% to 46.3% after the campaign. Causes of underutilization were: lack of different specialty consultants (62.4%), followed by deficient skills of doctors (51.2%) and irregular presence of female gynecologist (42.0%). Conclusion and Recommendation: Social marketing can improve health care utilization in rural sector, so it's recommended to disseminate the marketing materials on a wider scale to attract more customers, also better training of physicians in family units, continuous presence of a female gynecologist for better maternal care, a recommendation for the MOHP to financially support marketing campaigns for better results and further studies in this area should be carried out.