This paper reports the implementation of the Critical Incident Stress Management (CISM) Program with the German Air Traffic Control Services (DFS). Particular attention is paid to the application of CISM services to a population of air traffic controllers. An extended economic efficiency evaluation was conducted for the European Organization for the Safety of Air Navigation (Eurocontrol) Brussels. Questionnaires and interviews were obtained from forty-seven air traffic controllers (ATCOs), thirteen CISM peers, and the program manager. The collected data describe the goals of the program and their achievement, program implementation, costs, and benefits. The results revealed that after five years the program's estimated fiscal benefits had exceeded the costs (break-even). Moreover, it had improved the safety culture within DFS in many ways. For this reason, controllers who never consulted a peer reported many benefits of the program. They believed that having the program was a good idea as a back-up support in case they would ever need it.