A discussion of the nasal harmony of Aguaruna, a language of the Jivaroan family in South America, approaches the subject from the viewpoint of generative phonology. This theory of phonology proposes an underlying nasal consonant, later deleted, that accounts for vowel nasalization. Complex rules that suppose a complex system of vowel and consonant deletion are stated. Issues such as geminate structures and cyclicity of syllable structure assignment are specifically addressed, and the applicability of a number of theoretical conditions is examined. Specifically, the Linking Constraint proposed by Hayes (1986) and the Uniform Applicability Condition proposed by Steriade and Schein (1986) for geminate structures are examined as well as Harris (1983) argument with regard to the relationship between the strict Cycle Condition and the cyclicity of syllabification. Results indicate that the process of nasal harmony in Aguaruna has been well accounted for by mean of the Autosegmental Theory. (MSE)