Lung transplantation is proposed for young patients with a severe disease that can be expected to be fatal within less than two or three years. The main indications are chronic respiratory failure induced by chronic obstructive lung disease, cystic fibrosis or pulmonary fibrosis, and severe primary or secondary (Eisenmenger syndrome) pulmonary hypertension. The type of transplantation, determined after an exhaustive work-up ruling out all contraindications, is generally a single lung transplantation if there is no bronchial infection or two-lung transplantation or heart-lung transplantation in case of bronchiectasis or pulmonary artery hypertension. Survival at 1, 3 and 5 years is 72, 57 and 43% respectively. Transplantation improves exercise capacity, quality of life and lung function. It normalizes hematosis in case of chronic respiratory failure and pulmonary hemodynamics in case of pulmonary hypertension. The risk of complications, dominated by infections and rejections, requires careful clinical, functional and endoscopic follow-up. Bacterial infections are frequent during the first weeks. The frequency of opportunistic infections can be reduced by anti-infectious prophylaxis strategies. The rejection can occur as an acute episode, frequent during the first 100 days, or is sometimes asymptomatic. Chronic rejection or obliterating bronchiolitis is the main mid-term complication after lung transplantation and is responsible for the low long-term survival rate with recurrent secondary infections due to frequent bronchial colonization with Pseudomonas aeruginosa. Improved prognosis of lung transplantation requires the development of new immunosuppressive agents with lower risk of infection and chronic rejection observed with current treatments.