The present research investigated analogical transfer during problem solving by bilinguals. In a study with 50 Spanish-English bilinguals, participants solved a target problem whose solution was similar to that of a preceding source problem. The source problem was always presented in the 2nd language; the target problem was always presented in the 1st language. The results showed that when participants understood a key structural feature shared by the source and target problems, they solved the target problem more often than others. Participants' performance was not related to their proficiency in the language of the source problem (i.e., the 2nd language).