Residents frequently learn emergency radiology simply by on-the-job experience. As an educational tool and as a credentialling vehicle, the authors developed an examination consisting of imaging unknowns as well as written questions. The authors have administered the test each of the last three years. After initial apprehension, the residents became comfortable with the annual examination. They now regard the follow-up conferences as the best-organized instruction in emergency radiology in the training program. The authors' experiences suggest that in-house examinations can serve as an important means for teaching and credentialling in emergency radiology.