Sound propagation in a typical automotive air handling system was studied using the finite element and boundary element methods. The focus was on sound propagation characters and critical resonant frequencies of the system. A given sound source was applied as the excitation to the system. Frequency response analyses were performed, emphasizing the low and mid frequency ranges. The predicted critical frequencies, associated modal configurations, and corresponding sound pressure level fields were investigated. Both the finite element and boundary element methods were applied, and results by the two methods were compared and discussed.