Oral Corrective Feedback is a widely used teaching strategy that has been found to help language acquisition. The factors that contribute to its effectiveness, however, remain elusive. In this study, the role of smiling during teachers' OCF provision is investigated in intact language classrooms by modifying the analytical framework developed by Lyster and Ranta (Stud Second Lang Acquis, 19(1):37-66, 1997), which determines OCF effectiveness by the success of the learner uptake. In addition to the feedback strategies used, this study examines teacher smiling during the feedback instances, and whether they were genuine or polite smiles. The Facial Action Coding System (Ekman & Friesen, Environ Psych Nonver, 1(1), 56-75, 1976; Ekman, Friesen, & Hager, Facial Action Coding System: The Manual on CD ROM. Salt Lake City, UT: Research Nexus division of Network Information Research Corporation, 2002) is utilized to operationalize smile genuineness. Significant findings indicate that when teacher smiling is genuine, learners are more likely to correct their errors, while polite smiles do not have the same effect.