Aymara vowels delete under predictable phonotactic, syntactic, and morphophonemic conditions. We provide a detailed description of each of these processes, with special attention to morphophonemic vowel deletion. In this process, specific suffixes trigger the deletion of the preceding vowel, with no obvious phonological or semantic conditioning. This is both the most common type of vowel deletion in Aymara, and the most unusual one in cross-linguistic terms. We compare vowel deletion in Contemporary Aymara (Coler 2014) and Historical Aymara as attested in the 17th century (e.g. Bertonio 1612a) and reveal that both varieties delete vowels as a result of processes arising from phonotactic and morphophonemic motivation, though some processes of syntactic vowel deletion were not widespread in the historical variety. Notably, while morphophonemic vowel deletion was attested in both Contemporary and Historical Aymara, the suffixes which are lexically pre-specified to delete the preceding vowel are often different in the two varieties. Further, Historical Aymara lacks accusative inflection marking with subtractive disfixation, which is an important and typologically unusual aspect of Contemporary Aymara nominal morphology. In light of the typological rarity of morphophonemic vowel deletion (and disfixation in particular), we expect this description to be of interest to typologists.