Dyspnoea and exercise intolerance are common clinical manifestations in patients with sarcoidosis. The aim of this study was to explore the ventilatory response to exercise and oxygen kinetics during maximal exercise in patients with sarcoidosis as compared to healthy subjects. Thirty nine consecutive patients with sarcoidosis and 11 healthy volunteers underwent maximal cardiopulmonary exercise test (CPET) on a treadmill. Maximal oxygen consumption (VO2 peak) and the first degree slope for oxygen consumption during early recovery (VO2/t-slope) were measured. Tidal flow-volume loop during exercise was utilized to identify expiratory flow limitation (EFL). At peak exercise, EFL was observed in 53% of patients with sarcoidosis and in none of the healthy subjects (p<0.001). The presence of EFL in patients with sarcoidosis was independent of the stage of the disease and the treatment with corticosteroids. VO2 peak, breathing reserve and VO2/t-slope were lower in patients with sarcoidosis (23.0±6.0 ml/kg/min vs 34.5±7.6 ml/kg/min p<0.001, 28±17 vs 36±12 p<0.05 and 0.9±0.4 vs 1.1±0.6 p<0.05 respectively). In conclusion our data constitute a useful approach to the understanding of the pathophysiological mechanisms which might be involved in exercise intolerance in patients with sarcoidosis. Pneumon 2001, 14 (2): 140-147