Mycobacterium abscessus is increasingly recognized as an important pathogen in some individuals with advancing lung disease related to cystic fibrosis (CF). Because of its resistance to antimicrobial agents and virulence, its presence in the lungs of potential lung transplant recipients can be problematic. We present 2 cases of individuals with CF in whom M. abscessus was present in the preoperative sputum cultures. The organism manifested different degrees of invasiveness in the 2 cases after transplantation with different outcomes, suggesting an approach to future candidates for lung transplantation that may be of clinical significance to their physicians and surgeons.