The developing world is undergoing a ‘Pentecostal Revolution.’ Sociologists and religious scholars have extensively studied the astounding growth of this form of Protestantism; however, it has received relatively little attention from economists and policy makers and even less empirical research. Growing qualitative evidence indicates that some Pentecostal groups are making positive contributions to society through engagement with both members of their congregations and their communities at large, focusing on education, health care, and economic development. This paper proposes and tests the hypothesis that higher levels of Pentecostalism in a less developed country are associated with improved child mortality rates. Using a cross-country, multivariate analysis, it ultimately focuses on two categories of countries: those with less than $3,000 GDP per capita and Latin American and Caribbean (LAC) countries. This analysis indicates the proportion of Pentecostals in a country is associated with worse child mortality outcomes in countries below $3,000 GDP per capita. Conversely, in LAC countries, Pentecostalism is associated with improved child mortality rates. The results suggest a country’s context (politics, culture, etc.), the beliefs and/or practices of Pentecostals, or the actual percentage of Pentecostals in a country may influence the effect Pentecostals have on child mortality rates. Though Pentecostalism is complex and far from homogeneous, it may exhibit a positive effect on social development in certain cultures and contexts. Governments and NGOs – specifically in Latin America – should consider partnering with local, national, and international Pentecostal groups to meet a country’s social development goals. Not only might this increase the effectiveness of government programs, but it could also reduce implementation costs.