The authors evaluated in a retrospective investigation the effectiveness of adjuvant postoperative chemotherapy (ChT) and radiotherapy (RT), as compared with surgery alone, according to morphological types and stages of cancer lung (CaP). In a group of 321 patients 143 were treated by operation alone, 36 by operation and RT and 53 by operation and ChT. ChT involved administration of Cyclophosphamide, 30 mg/kg, at three-week intervals, some of the patients were also given vincaalkaloids. Therapy was repeated after 6-month intervals. According to the gross mortality data the probability of survival (PP) was compared by Kaplan-Meier's method. Improved PP was proved in patients with small cell lung cancer (MbCa) treated by operation and ChT and in third-stage disease treated by adjuvant ChT. In stage I of CaP adjuvant ChT and RT cause deterioration of the perspective of survival, as compared with operation alone and in stage II adjuvant ChT and RT are no advantage. The authors recommend adjuvant ChT in patients with surgically treated small-cell carcinoma and in stage III of operated CaP. They draw attention to the different response of tumours to adjuvant ChT and RT according to types and stages of CaP, to the fact that RT does not prolong the survival and to the possibility of preoperative ChT and RT in some types and stages of CaP.