The increase in cancer incidence with increasing age is becoming more obvious and more important as the average age of population increases. Currently over 50% of all cancers occur in people who are 65 and older. The clinical behaviour of common malignant diseases may change with age because of intrinsic variation of the neoplastic cells and the ability of the tumor host to support neoplastic growth. Therapeutic decisions should be based on an estimation of patient's life expectancy, functional status, comorbidity, polypharmacy, socioeconomic conditions, nutrition and the presence of geriatric syndromes. This review should give some answers to the many existing questions about cancer in the elderly.