The aim of this study was to characterize the influence of neurological lesion level on the cardiorespiratory and ventilatory responses of two groups of paraplegic athletes during incremental exercise on a treadmill and in the usual conditions for wheelchair exercise. Cardioventilatory responses was evaluated in two groups of paraplegic wheelchair sportmen : 6 athletes with lesion levels between the fourth and eighth thoracic vertabrae (T4-T8) and designated as high paraplegic athletes (HPA) and 6 athletes with level between the eleventh thoracic vertabrae and the fifth lumbar vertabrae (T11-L5) and designated as low paraplegic athletes (LPA). After a clinical examination with a resting electrocardiogram and spirometry to determine lung volumes and bronchial flows, the subjects were equipped with the expired gas collection system. After two minutes of data collection at rest and three minutes of warm-up at 4 km.h-1, treadmill speed was increased by 1 km.h-1 every minute until exhaustion. During this test, ventilation and its components, as well as respiratory exchanges, were measured breath by breath (C.P.X. Medical Graphics). Oxygen uptake (VO2), carbon dioxide output (VCO2), minute ventilation (VE), respiratory exchange ratio (R), heart rate (HR), tidal volume (Vt), the ratio of inspiratory time (It) to the total respiratory cycle (Trc), mean inspiratory flow (Vt/It) and breathing frequency (f) were calculated every minute by taking the mean of the last 20 second of each increment. The spirometric values presented no significant differences between groups. At rest, no significant difference was observed between the two groups for all cardiorespiratory and ventilatory values obtained during the treadmill test. At submaximal exercise, all variables increased with the augmentation in workload. With the exception of R, there were no significant differences in the classic cardiorespiratory parameters (VO2, VCO2, HR, VE) between the two groups of paraplegics. For the ventilatory parameters, we observed significant differences between the two groups, with values of f and It/Trf significantly higher (0.01