Abstract: In this communication a bi-criterion approach for the nominal Airlines Crew Rostering Problem is developed. The nominal Crew Rostering Problem considers the assignment of the crew staff to a set of pairings covering all the scheduled flights so that operations costs are minimized while its solution must meet hard constraints resulting from the safety regulations of Civil Aviation as well as from the airlines internal agreements. Another goal is of the highest interest for airlines : since the overall satisfaction of the crew staff may have important consequences on the quality and on the economic return of the operations. In this communication, a new mathematical formulation of the crew scheduling problem which takes into account the satisfaction of the crew members is proposed. A heuristic approach, combined with a genetic algorithms technique, is adopted to produce reduced cost solutions associated to acceptable satisfaction levels for the crew staff. The application of the proposed approach to a medium size Airline Crew Rostering Problem is evaluated.