20 male patients were treated for various tumors, most of them by combination therapy program including Cis-diammino-dichloroplatinum, Methotrexate and Bleomycin, the mean total dose for this last drug being 225 mg in 3 months (75 mg-300 mg). Spirometric tests, carbon monoxide diffusing capacity (DLCO) and its components Dm (membrane diffusing capacity) and Vc (capillary blood volume) were performed before each course and at the end of the chemotherapy, to assess their value in detecting Bleomycin pulmonary toxicity. There was no statistically significant change in any ventilatory nor diffusional test among these 20 patients, carefully selected for the absence of cardiopulmonary history. There was a slight decrease of DLCO for 3 patients having received 300 mg of Bleomycin. The lack of cardiopulmonary history, the mean total dose under the toxic threshold, and perhaps the insufficient delay between the end of the treatment and the last control test, may explain this absence of variability of functional tests.