Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae is spreading globally and represents a challenge in infection control and treatment. Solid organ transplant (SOT) recipients are especially at risk for infection by multidrug-resistant bacteria, and little is known about infection with KPC-producing organisms in this setting. The aim of this study was to describe the clinical and microbiologic aspects of KPC-producing K. pneumoniae infections in SOT recipients. A KPC-2-producing K. pneumoniae outbreak was identified in a public teaching tertiary care hospital in São Paulo, Brazil, in June 2009. During the outbreak, cases of KPC-2-producing K. pneumoniae infection in SOT recipients occurred between July 2009 and February 2010; these cases were retrospectively reviewed. Overall, 12 episodes of infection with KPC-producing K. pneumoniae occurred in 2 heart, 4 liver, and 6 kidney transplant recipients with incidence rates of 16.7%, 12.9%, and 26.3% in heart, liver, and kidney transplantation, respectively. Infection occurred at a median time of 20 days after transplantation. Primary infection sites were as follows: 4 urinary tract infections, 4 bloodstream infections, 2 pneumonias, and 2 surgical site infections. All patients except one had received antibiotics in the last 30 days, mostly piperacillin-tazobactam or glycopeptides. All strains exhibited susceptibility to amikacin and gentamicin. Patients were treated with tigecycline plus polymyxin B (3 cases), polymyxin B plus carbapenem (3 cases), polymyxin B alone (3 cases), or tigecycline plus imipenem (1 case). In 2 cases, patients received only carbapenem, and death occurred before the final culture result. The overall 30-day mortality rate was 42%. In this series of KPC-producing K. pneumoniae infection in SOT recipients, the infection occurrence was high during an institutional outbreak and was potentially life threatening.