Thirty-six heart-lung and lung transplantations have been performed in Denmark from January 1992 to January 1994. Heart-lung transplantations was initially carried out in patients with pulmonary vascular diseases. Single lung, double lung and heart-lung transplantation have become therapeutical alternatives and the indications have been expanded to terminal patients with pulmonary diseases. Careful selection of patients and donors, careful surgical techniques and a stringent immunosuppressive treatment have minimized the perioperative mortality. Daily lung function measurements, transbronchial biopsies and bronchoalveolar lavage have created possibilities for an early and safe diagnosis of infections and rejections. A high frequency of obliterative bronchiolitis with loss of pulmonary function is still a serious and unsolved problem. Intensive investigations with the aim of understanding, preventing and treating obliterative bronchiolitis are going on.