AbstractIn a multicentre study, the Eysenck personality questionnaire (EPQ) was administered to patients in the diagnostic process for lung diseases, who later on turned out to have lung cancer or other chest disease. The study was controlled by a group of healthy persons. The most important results of the survey are relatively low values for extraversion in the carcinoma group (BCA) and relatively high scale values for extravertion both in the healthy (GKG) and in the sick (KKG) control groups. Higher neuroticism scale values are shown by younger carcinoma patients (BCA) in comparison with healthy (GKG) and patient control group persons (KKG). However, psychotocism scale values show just small differencesk between BCA on the one hand and the control groups (GKD and KKG) on the other. Finally the authors discuss whether the results of the study are more supportive of Cooper's stress hypothesis than of Eysenck's constitutional hypothesis as explanation for an important partial cause of carcinogenesis.