Immunization is a very effective strategy to prevent against common infectious disease. The objectives of the study were to determine the immunization status and reasons for non-vaccination of children coming to Civil Hospital Sukkur. This cross-sectional study was conducted pediatric OPD at Civil Hospital Sukkur from January 1, 2013, to June 30, 2013. Parents of children under five years of age brought their child to Outpatient Department of Civil Hospital Sukkur for any illness were asked to participate in the study. Parents who gave informed consent were included in the study. Data were collected using a small questionnaire by the researcher himself. A total of 500 parents gave consent to participate in the study. The average age of children was 20.4±16.3 months, 257 (51.4%) were males and 243 (48.6%) were females. Four hundred and four (80.4%) children were fully vaccinated and 98 (19.6%) were not vaccinated. Parents don't know about immunization, busy parents, illness of a child, fear of immunization and parents who are not considering immunization as important are independent factors of non-vaccination. Sukkur, Instructor, research, Department of Community health Sciences, Aga Khan University Karachi, Fifteen percent of Pakistan population constitutes children under five years of age. These children contributed 50% of overall mortality compared to 8-10 in high-income countries [3]. The rate of mortality of children under five years of age is high in South Asian countries. According to the World Bank, the under-five mortality rate is quite high for Pakistan 81/1000 live births (LB) compared to India 48 and Bangladesh 38/1000 LB.[4] Communicable diseases are a major cause of under-five mortality. To develop preventive measure against communicable diseases, a pilot project of expanded program of immunization (EPI) had been launched in 1974. In 1985, this program was further augmented by accelerated health plan of government (AHP) which resulted in improving coverage from a low 5% to 70% in 1984. [5,6] in the last decade national immunization days (NIDs) and the mopping up campaigns (door to door vaccination in high-risk areas) have been introduced to provide maximum coverage [7,8].In developing countries, vaccinating children has the highest impact on health intervention that not only reduces hospitalization but also decreases the treatment cost through prevention [9,10] The vaccine coverage varies according to the province of Pakistan. According to recent Pakistan Demographic and health survey (PDHS) 2012(PDHS) -2013