Flight cancellations are costly to airlines and air passengers, but the question is, how costly? Little quantitative analysis about cancellation cost has been done, and current studies are focused on flight delays. However, cancellations should be studied to supplement delay metrics to assess the performance of the National Airspace System, as well as to evaluate the effectiveness of air traffic management. Postoperation data of the ground delay program were explored, and relative value of cancellations in terms of delay savings were inferred. Two cancellation metrics were developed for this purpose. In addition, flight cancellation decisions were modeled with a discrete choice model by using the two cancellation metrics that were generated as well as some other flight characteristics. Three models are presented in this study. The results reveal the value of a flight cancellation and airline preference structure in making decisions in canceling a flight in response to schedule disturbance. The study contributes to the literature in a distinct way: postoperation data are used to understand airline flight cancellation behavior in the context of ground delay programs.