The textbook summarizes current knowledge regarding epidemiology, risk factors, clinical symptomatology, diagnostics and treatment possibilities of most oncological diseases, including childhood cancers and haematological malignancies. The general onkological part also discusses the mechanisms of cancerogenesis, histopathology of tumors, hereditary cancer syndromes, available modalities of local and systemic anticancer treatment and most frequent side effects of this treatment, principles of palliative care and, last but not least, communication and psychological aspects of cancer care. Special emphasis is placed on acute conditions in oncology and the possibilities of their solution. The scope of the text covers most of the information required to pass the exam in the subject Clinical Oncology at the Faculty of Medicine of Masaryk University in Brno.