This study, based on Helmreich and Merritt’s (1998) definitions of professional and organizational cultures, identifies the challenges faced by airlines in the United States and India in the implementation of MHF/MRM programs. Data was gathered through ethnographic observations and field interviews (n=350) at two major airlines in the United States and one regional airline in India. The results of this study indicate the following barriers at the professional and organizational levels. At the professional level, an appropriately qualified AMT or AME holds individual airworthiness authority; whereas, the human factors training promotes team performance. Unless specific mechanisms are developed so that the individual AMTs and the AMEs are not coerced into releasing an aircraft in a hurry, the implementation of MHF/MRM programs will not be successful. At the organizational level, there is limited evidence that any of the comparison companies have integrated safety as a core corporate value. Consequently, MHF/MRM programs depend on support from a few key managers and union representatives. If these key people are reassigned, their MRM/MHF programs are likely to fade.