The quality of Spanish vowels is often described as being relatively stable across Spanish dialects compared to consonants. Nonetheless, shifts in vowel quality are observed in a number of contexts (e.g., Oliver 2007, Garrido 2007, Willis 2008). For Spanish in contact with Ecuadorian Quichua, stressed vowels also showed differences in quality amongst bilinguals according to age of acquisition (Guion 2003). In addition to the three vowel phonemes /i a u/ found in Quichua, Southern Peruvian Quechua also has mid-vowel allophones [e o] that appear with uvulars. In the present study, the Spanish vowel quality of Lima monolinguals is compared to that of Cuzco monolinguals and bilinguals (early 'native' vs. late 'L2') in order to examine the effect of contact with Quechua. Measurements of first and second formants (F1 and F2) demonstrate regional differences between Lima and Cuzco as well as variation amongst Cuzco groups. These data suggest that vowel quality in Spanish may be influenced by languages in contact, with early bilinguals behaving differently from both the Cuzco monolinguals and late bilinguals.