This study investigates the effects of perceptual training on Brazilian English language learners’ ability to acquire preantepenultimate stress, or stress on the fourth to last syllable. Since preantepenultimate stress assignment is infrequent in Brazilian Portuguese (BP), it was initially hypothesized that BP speakers would store few examples of this pattern. The training was performed in five sessions and included stress identification tasks followed by immediate feedback. Results confirm the training significantly improved study participants’ perception and production of preantepenultimate syllable stress assignment. Furthermore, participants generalized acquired production patterns to unfamiliar words and retained these patterns for two months after training concluded. With frequent perceptual training, it is believed BP speakers could create a new category of English words with preantepenultimate syllable stress. This study demonstrates that perception training, typically used for the perception or the production of sounds, can also be used to improve the production of L2 stress assignment with very positive results.