This study examined the effects of semantic and structural elaboration on second language (L2) lexical acquisition. English-speaking low-intermediate L2 Spanish learners attempted to learn 24 new Spanish words in three conditions: (a) make pleasantness ratings about each word referent based on previous experiences (+semantic); (b) count letters in each word (+structural); and (c) “do your best” only (no elaboration). Dependent variables were free recall of the target words in Spanish, free recall of the target words in English, and cued recall (generate Spanish words when presented with pictures). Results indicated higher Spanish free recall for +structural than for +semantic; higher English free recall for +semantic than for +structural; higher overall recall for no elaboration than for +semantic and +structural; and higher cued recall for control than for +semantic and +structural. The results provide evidence that increased semantic processing can inhibit one's ability to encode the formal properties of new words.