This study investigates how motivation and interaction shape the speaking proficiency of study abroad (SA) and classroom or at home (AH) language learners. The author administered a motivation questionnaire, language contact profile, and pretest and posttest simulated oral proficiency interview. The data reveal that SA and AH students had similar motivational profiles. As expected, SA participants used the target language outside of class more than their AH counterparts. Furthermore, SA students improved their speaking proficiency more than the AH group. Student motivation and interaction were identified as important factors in the development of speaking proficiency in both learning contexts. Results suggest a potential role for explicit instruction in language learning strategies and approaches that enhance students' motivation and interaction with the target language culture. Discussion focuses on how to use the positive features of the SA environment to enhance AH instruction. (Contains 6 tables, 1 figure, and 4 notes.)