Oncological treatment consists of surgical treatment, chemotherapy, and radiotherapy, which affect healthy and tumor tissue differently. Their use can have a systemic (chemotherapy) or local (radiotherapy) effect. Unfortunately, its' use may lead to numerous types possible tissue damage, one of which is cardiotoxicity. This phenomenon can manifest itself in various ways and cause a wide range of clinical conditions and symptoms, from asymptomatic heart rhythm changes to heart failure, shock, and even death. The most common clinical presentation of cardiotoxicity of oncological treatment are arrhythmias, chest pains, hypertension, bradycardia and heart failure. Despite this, there are no clear diagnostic criteria for carditoxicity for most chemotherapeutic agents, nor can the connection between therapy and cardiovascular problems be fully proven. Therefore, supervision and monitoring of various diagnostic values and criteria are important. One of the most important is LVEF, which is a diagnostic criterion for anthracycline cardiotoxicity. For others, the criteria are not so strictly defined, but with regular ECG measurements, laboratory tests, and echocardiograms, suspicion can be raised in time and cardiotoxicity can be detected and sometimes prevented while the damage is still reversible. The treatment is usually stopped when some symptomatic cardiotoxicity is proven, and sometimes also in asymptomatic cases. The continuation of chemotherapy depends on a lot of factors which include the chemotherapeutic agent and its properties, guidelines of various governmental agencies, the level of tissue damage and lastly, the risk-benefit ratio of a rechallenge with the same agent.