Patients with malignancies are subject to develop a unique set of urgent and life-threatening complications. These emergency problems can be the result of the disease itself, the result from the therapy directed against the cancer or the result of previously existing pathological conditions not related to cancer. In some cases, these problems are the first symptom of the tumor. Aim: The aim of this study was to review the literature regarding the oncologic emergencies. Method: The method of this study included bibliography research from both the review and the research literature, mainly in the on-line data base 'Pubmed'. Results: Tumor lysis syndrome, malignant spinal cord compression, superior vena cava syndrome, cardiovascular emergencies, acute renal failure, venous thrombosis and pulmonary embolism, metabolic emergencies, neutropenic infection, acute pulmonary problems, acute hemorrhage and hematuria are the most important oncologic emergencies. Conclusions: Early diagnosis of the oncologic emergencies and prompt interventions can be lifesaving. However, staging of the tumor, response to current treatment, overall prognosis and patient and family wishes should be assessed in order to establish an appropriate treatment plan.