The cancer and cancer treatments, including chemotherapy, radiation therapy, and surgical interventions, have crucial adverse cardiovascular effects. The hemodynamic problems are associated with direct cardiovascular complications of cancer, cancer-related complications, and complications from cancer therapy. Thus, these cancer patients have high burdens of severe, disabling, or life-threatening illnesses. The impacts involve all dimensions of hemodynamic function according to preload, contractility, afterload, cardiac rhythms, pulmonary circulation, and myocardial oxygen balance. Therefore, it is necessary to have careful hemodynamic evaluation before, during, and even after the end of treatment. The integration of clinical evaluation and hemodynamic monitoring can lead to better understanding of pathophysiology and guide effective management. Hemodynamic monitoring in oncologic critically ill patients should involve both macro-hemodynamic and microcirculation parameters in order to achieve a better result of the resuscitation. The first step of monitoring is to recognize patients with circulatory insufficiency (hypotension, low cardiac output, tissue hypoperfusion) and then using any functional hemodynamic monitoring that is proper to individual patient to figure the fluid responsiveness. In non-fluid responder, the minimally invasive cardiac output monitoring and basic echocardiography will play an important role to identify specific causes (e.g., cardiac tamponade) and adjust vasopressor and inotrope titration. Finally, microcirculation monitoring like lactate clearance should be used to tract a result of resuscitation.