Acoustical comfort is one of the key factors in an airport passenger terminal. Speech intelligibility in the airports is often affected by high level of ambient noise and long reverberation time caused by reflective materials. The acoustical condition in passenger terminal of a large airport was investigated by conducting acoustical field measurements. Additionally, computer simulations were done to evaluate acoustical factors in selected spaces. The outcome of both field measurements and computer simulations was a detailed evaluation of existing acoustical condition, and were compared to the acoustical design requirements. Finally, based on the results, design recommendations were provided to improve acoustical conditions in the investigated airport.