Mega-cities - sprawling urban centres - are now home to most Latin Americans. This work contrasts religion in two such cities - Sao Paulo in Brazil and Caracas in Venezuela. In Brazil, the Catholic Archdiocese of Sao Paulo, under Cardinal Arns and progressive Catholics, was a rallying point for resistance to the military dictatorship. Sao Paulo is also a city in which Pentecostal Protestant churches have enjoyed explosive growth. The author aims to give a sense of what is happening within both the Catholic and Protestant communities. Venezuela's capital city is very different. Characterized by one Protestant missionary as a secular city, Caracas is a place where relative wealth and consumer lifestyles have proved obstacles to the spread of Christianity. Here, both Protestant and Catholic churches face quite different challenges to those in Sao Paulo.