This dissertation presents a description of the morphology and phonology of Zihuateutla Totonac (ZT), a member of the Northern branch of the Totonacan (Totonac-Tepehua) language family. Zihuateutla Totonac is spoken by about 1,100 people in northern Puebla State, Mexico. Previous to this study, ZT had no description of its linguistic features, and its relationship to other languages in the family has been poorly understood. Based on a documentation project conducted between 2013 and 2017, this research contributes to our knowledge of the unique linguistic properties of ZT that distinguishes it from other languages in the family. The outcome of this project includes a phrasal and textual corpus, a lexical database, and a detailed description of major phonological and morphological patterns. This description covers an overview of basic syntactic structures, the phonemic inventory, and general phonological processes. The bulk of this thesis involves the morphological patterns of the main word classes (verbs, nouns, adjectives, numerals, and adverbs). Of typological importance is the highly polysynthetic and agglutinative verbal morphology of ZT, which encodes categories for inflection and derivation, and categories that do not fall in either of these two domains. Nouns, adjectives, numerals, and adverbs also show some unique functions and morphological features that contribute to our understanding of the structure of natural language. The description of the inflectional and derivational properties is presented proceeding in the direction from form to function, showing regular and compositional patterns and then listing idiosyncratic or lexicalized expressions. The thesis contributes to our understanding of the dialectological relation of Zihuateutla to other languages in the Northern branch for which there is documentation and forms the basis of a linguistic record for typological studies and future generations.