This study explores the impact of a classroom intervention on second language (L2) Spanish learners' attitudes towards bilingualism and language learning. Language attitudes are crucial to student success (Cummins, 2000), influence students' decisions to continue language learning (Bartley, 1970) and can start developing as early as childhood (Dekker et al., 2021). While attitudes towards the language learning experience can improve through study abroad (Artamonova, 2023), recent research has also highlighted the potential of metalinguistic lessons to influence language attitudes within the L2 classroom setting (Lanvers et al., 2019). Given that knowledge about a topic will affect one's attitudes (Artamonova, 2020), this study aims to assess whether a lesson about bilingualism can improve students' language attitudes. Participants were 178 L1 English and L2 Spanish students enrolled in first through fourth level Spanish courses across four Midwestern universities. An experimental group received the lesson about bilingualism before completing a survey that assessed their language attitudes. A control group completed the survey before receiving the lesson. Results from a subset of data show that the experimental group exhibited more positive attitudes towards bilingualism and language learning than the control group in attitudinal questions that were explicitly addressed in the lesson. The class level of participants was another predictor of language attitudes, with lower-level students having fewer positive attitudes overall as compared to higher-level students. This study offers valuable insights into a realistic approach to improving attitudes within the classroom setting and inspires future research on metalinguistic lessons in language classes.