Lexical stress assignment plays a central role in being understood in a second language. In fact, research has shown that it may be more important for the comprehensibility of second language learners' speech than, for example, grammatical correctness (Trofimovich & Isaacs, 2012). Nonetheless, its production poses challenges for second language learners. This study investigated the effect of perceptual training on the production of three types of predictable German lexical stress patterns by native speakers of English. Beginner and intermediate learners produced German words from three categories: words ending in schwa; words with unstressed suffixes; and German-English cognates. The results demonstrate that both beginner and intermediate learners improved in their production of lexical stress after the training. Though participants in both groups had more difficulties in assigning lexical stress to cognate words than to non-cognate words, production accuracy could best be predicted by the presence of certain suffixes. The results have implications for teaching second language vocabulary.