This article presents the case of Guatemalan Pentecostalism as a highly relevant expression of Latin American Pentecostalism that helps to clarify the debate about the syncretic nature of Pentecostalism. We use the Guatemalan case to test the thesis of Juan Sepúlveda, a Chilean Pentecostal historian and theologian, who explains the success of Latin American Pentecostalism in light of its syncretic character. His argument about the syncretic character of Pentecostalism is based on the Chilean case. Paying attention to its historical development, we present Guatemalan Pentecostal theology in relation to traditional Mayan culture and religion and in relation to popular Catholicism and traditional Latin American Protestantism. Specific attention is paid to the espoused theology of Pentecostal pastors as they provide an account of indigenous Pentecostals’ lived faith. Finally, we answer the question: Does Juan Sepulveda’s approach (still) provide an adequate framework for the theological assessment of possible syncretic characteristics of (Latin American) Pentecostalism? The Guatemalan case indicates ways to improve certain limitations of Sepúlveda’s approach, such as its static understanding of culture and its exclusion of the theological understanding of syncretism.