Some people ascribe successful language learning to an innate aptitude that cannot be further developed, at least after a certain young age (i.e., an entity mindset), while other people believe that language learning ability can be improved (i.e., an incremental mindset). The purpose of this research is to (a) introduce the Language Mindsets Inventory (LMI), and (b) test the mindsets-goals-responses model, which maintains that learners' mindsets predict the goals that they set for language learning, and that these goals in turn affect how they respond to difficult academic and communication episodes. Correlational and factor analyses provided evidence of the LMI's valid and reliable use in research with university-level language students. Path analyses showed that regardless of their competence level, greater endorsement of an incremental mindset was associated with the goal of learning more about the language, and this learning goal in turn predicted greater mastery and less helpless responses in failure situations. Greater endorsement of an entity mindset predicted the goal of demonstrating competence (i.e., performance approach goals) when students believed that they had stronger language skills. The use of the LMI in future research and the importance of supporting incremental mindsets for language education are discussed.