The concept of religion and its practice within ancient societies across the world is a subject that has fascinated scientists for centuries. The pre-Columbian Maya codices, first-hand Postclassic hieroglyphic documents, have been examined by hundreds of anthropologists. Analysis of these books has led scientist to hypothesize that these manuscripts were vitally connected to the Maya Postclassic belief system. Understanding the central focus of a civilization's religion and how, why and under what circumstances the religion is practiced truly distinguishes them as a culture. The intent of this thesis is to examine the role of rain in Maya Postclassic religious belief. Through an examination of Postclassic Maya ethnographies, archaeological evidence and the Maya Dresden, Paris and Madrid codices, this thesis evaluates the major theme of rain that is threaded throughout the culture and religion of the Maya people. By cross referencing ethnohistoric, ethnographic and archaeological evidence, it is revealed that rain was a fundamental-part of Maya religious practice as: 1) a symbol of fertility, 2) a phenomenon that people actively sought to control through religious practice and 3) as a fundamental building block of the Maya universe, construed broadly to encompass both the natural and divine elements of the universe.