Universities and students increasingly view internships as valuable learning experiences that complement and augment academic classroom learning. Students benefit from the opportunity to apply recently acquired knowledge in the 'real world,' to identify knowledge gaps that they should address in future coursework, and to secure a post-graduation job. But, benefits beget costs because nothing is free in life--including internships. Our econometric analysis employs two modeling techniques to measure the academic effects undergraduate business students experience when they complete a mandatory internship while concurrently taking academic courses. After controlling for a number of student- and curriculum-related factors, we find students' academic performance was negatively affected by the internship while it was ongoing. Although academic performance did rebound after the students completed their internships, it did not fully recover. Our findings suggest that faculty and administrators cannot determine the appropriate curricular role for college internships without fully considering their academic effects.