AbstractThe present study examined vowel-to-vowel (VV) coarticulation in backness affecting mid vowels /e/ and /o/ in 36 Spanish nonwords produced by 20 native speakers of Spanish, aged 19–50 years (mean = 30.7; SD = 8.2). Examination of second formant frequency showed substantial carryover coarticulation throughout the data set, while anticipatory coarticulation was minimal and of shorter duration. Furthermore, the effect of stress on vowel-to-vowel coarticulation was investigated and found to vary by direction. In the anticipatory direction, small coarticulatory changes were relatively stable regardless of stress, particularly for target /e/, while in the carryover direction, a hierarchy of stress emerged wherein the greatest coarticulation occurred between stressed triggers and unstressed targets, less coarticulation was observed between unstressed triggers and unstressed targets, and the least coarticulation occurred between unstressed triggers with stressed targets. The results of the study augment and refine previously available knowledge about vowel-to-vowel coarticulation in Spanish and expand cross-linguistic understanding of the effect of stress on the magnitude and direction of vowel-to-vowel coarticulation.