This study is aimed at investigating factors leading to delayed oncologic examinations versus immediate consultation with a physician in patients with various cancers. We analysed the results of a study of patients (n = 291) reporting for their first oncologic examinations. We conducted structured interviews containing social, demographic and clinical data, the Spielberger State-Trait Anxiety Inventory, the Beck Depression Inventory and Harris and Guten's health appraisal scores. Based on an analysis of decision-making trees, the results indicate that it is possible to predict beliefs regarding the curability of cancer and immediate versus delayed reporting to a physician. Delayed reports may be predicted on the basis of two factors: (1) a belief that cancer is incurable combined with increased state anxiety, 'good' or 'very good' self-appraisal of health and low depression; and (2) a belief that cancer is incurable accompanied by increased anxiety and depression. The characteristics of patients delaying a visit to the oncologist suggest the existence of three independent factors leading to both considerable (longer than nine months) and minor (up to one month) delays in seeking treatment.