In 36 patients with Duchenne muscular dystrophy we studied the growth pattern, the type and severity of the spirometric abnormalities, the evolution of the Motor Functional Class (MFC), the infectious complications and treatments. Their age ranged from 6 to 19 years and the MFC was from 1 to 9. Regarding height, up to 12 years we verified a slope of 5.69 +/- 0.58 cm/year (r 0.872 p < 0.001) and a posterior detention was observed. Of the 36 patients, 24 were below the percentile 5. The restrictive disorder prevailed. The forced vital capacity (FVC) expressed in % of the theoretical value showed a lineal fall with age, with a negative correlation (r 0.51, p < 0.01) of -3.5 +/- 0.83%/year. The deterioration of the MFC was marked starting from 6 years; with a slope of 0.84 +/- 0.14 points between 6 to 12 years (r 0.73 p x 0.001). Up to 14 years, the slope was 0.212 +/- 0.084 (r 0.49, p < 0.05). Patients older than 14 years had reached a greater CFM of 7; starting from this MFC a progressive fall of the VC was observed with a slope of -15.29 +/- 3.39% of CVF/CF (r 0.56, p < 0.001). Nine patients with respiratory infections were documented. Four were pneumonia and 3 of them required mechanical ventilation and died. Only 50% of the patients accepted rehabilitating treatment. Four patients accepted surgery of the alterations of the feet while the patients with deformation of the column underwent spinal stabilization.