We investigate whether a business curriculum develops critical thinking ability or at least serves as a filter for critical thinking (i.e., students who cannot think critically tend not to progress toward graduation). We measure critical thinking by performance on the Watson-Glaser Critical Thinking Appraisal Short Form which was administered to a sample of 600 students enrolled in a junior-level operations management course. We find that students who have completed more credit hours score significantly higher than those with fewer hours completed. This advantage appears specifically evident in the areas of interpreting information and evaluating arguments.