This chapter explains the concept of vulnerability and demographics of vulnerable populations. Poverty is the primary cause of vulnerability: It limits resources in many areas of life. From a public health perspective, a population is vulnerable by virtue of status, which means that some groups are at greater risk than others. Faith community nurses (FNCs) may have many or few opportunities to work with vulnerable persons, depending on the demographics of the faith community. Living in poverty decreases access to resources. It increases the likelihood that a person will experience adversity related to physical, psychological, and social health, as well as poor housing, nutrition, health care services, and education. FCNs need to be knowledgeable about programs such as social services, welfare, Medicaid, Women, Infants, and Children (WIC), and the Children’s Health Insurance Program (CHIP), as well as local food banks.