Introduction The Expanded Program on Immunization (EPI) has proven to be one of the most effective public health strategies, resulting in a dramatic reduction in the incidence of many communicable diseases. However, the literature contends that immigrants, some rural populations, and minorities have been associated with less compliance with vaccination calendars and schedules (1,2). The EPI started its operations in Turkey in 1981 when all vaccinations were provided free of charge in the primary healthcare centers located throughout Turkey (3). According to the 2008 Turkish Demographic and Health Survey Report, the complete vaccination coverage rate for children aged between 12 and 23 months in Turkey was 74.6% (4). However, in the Southeast Anatolia region, complete vaccination coverage was below the national average (66.7%), indicating a large gap in service utilization (4,5). Many studies have examined the barriers to childhood immunization, such as families' lack of knowledge or inaccurate perceptions about vaccines, inadequate transportation, inconvenient office hours, long queues, poverty, missed opportunities, religious and cultural factors, family size, the number of siblings, family mobility, health staff 's attitudes, parents' education level, minority status, race, and political instability (5-11). Existing studies also reveal that, in general, children of migrant farmworkers rarely enjoy preventive care (10,12); however, there are only a few studies defining the magnitude of risk that these immunization rates pose. Farmworkers' health service utilization is limited by their migrant lifestyles, lack of enabling resources, linguistic and cultural differences, lack of documentation, and the limited number of healthcare facilities in the agricultural areas of the world. Mobility also makes follow-up care (e.g., growth monitoring and immunization) and longterm care (e.g., for tuberculosis or diabetes) difficult to provide (13). Determining a population's vaccination status, identifying medically disadvantaged groups, and targeting vaccination barriers are critical steps in improving the intervention programs that promote vaccination in a health district. Aim: The Expanded Program on Immunization has proven to be one of the most effective public health strategies. However, the literature contends that medically disadvantaged groups have been associated with less compliance with vaccination calendars and schedules. The aim of this cross-sectional survey was to investigate the vaccination coverage of the children of migrant and seasonal farmworkers (MSFs) and to identify their specific barriers to vaccination. Materials and methods: A total of 168 children aged 12-23 months were recruited to the study from a primary healthcare center. Data were collected through a structured questionnaire targeting the issues of infant vaccination status, the reasons for vaccination failure, and sociodemographic data about the children and their families. Results: Childhood vaccination coverage in MSF children was found to be...