Spanish teachers' feelings of self-efficacy can provide an important measure of their abilities to be effective in the classroom and, perhaps, affect student achievement. There is a need for qualitative research focused on the lived experiences of inservice foreign language teachers while they are immersed in the target culture in order to better understand how those experiences can affect their instructional practices and teacher efficacy. Therefore, the purpose of this study is to examine current Spanish teachers' feelings of self-efficacy while participating in a summer study abroad program in Costa Rica. The following research question guided this inquiry: How does the study abroad experience affect Spanish teachers' feelings of self-efficacy as it relates to language proficiency and instructional practice? A multiple case study design (Stake, 2006) was employed using multiple data sets to analyze the participants' lived experiences while studying in Costa Rica during the summer of 2014. Four participants were selected that met the following criteria: (1) studying abroad in Costa Rica during the summer of 2014; (2) currently enrolled in a master's program in Spanish education; and (3) currently teaching Spanish in a 7-12 setting in the United States. The following data sets were collected from the participants: (1) individual participant interviews; (2) in-country observations of interactions; and (3) participant reflection journals. Three themes emerged from the findings: (1) after spending time in the target culture, all participants realized deficiencies in their language skills; (2) all participants developed a better understanding of their own students as a result of being a foreign language learner; and (3) all participants were committed to using the target language (Spanish) in their classrooms at least 90% of the time.