The paper presents the most important problems in the pharmacotherapy of mental disorders accompanying malignant tumours in the elderly. The most frequent psychopathological syndromes in this group of patients are briefly reviewed, with special focus on the difficult psychological situation of patients with a diagnosis of cancer. Attention is drawn to the need for careful selection of psychotropic drugs and to possible interactions with drugs of a different profile. Particular stress is given to the discussion of therapeutic procedures in depressive and anxiety syndromes – the most frequent concomitants of cancer. In an attempt to predict the outcome of pharmacotherapy it is stressed that it is necessary to adopt a proper approach to the patient and to select an appropriate strategy of informing the patient about the cancer diagnosis.