espite the fact that pericardial tumors are much rarer than other cardiac tumors and account for only 6.7-12.8% of all primary cardiac neoplasms, an increase in their diagnostic detection has recently been noted. Cardiac hemangiomas are rare vascular tumors of the heart, accounting for less than 10% of benign primary tumors. The vast majority of patients with cardiac hemangiomas are asymptomatic. However, the course of pericardial hemangioma is often accompanied by evident hydropericardium, which can interfere with diagnosis of the tumor.Purpose. To present the features of the diagnosis and management of a patient with effusion in the pericardial cavity due to cardiac hemangioma using a clinical example of a comprehensive examination, Materials and methods. Patient D., 73 years old, was referred by a cardiologist to the CT and MRI department with nonspecific complaints and severe pericardial effusion.Results. According to echocardiography, a pericardial tumor in the massive hydropericardium was suspected. Cardiac MRI confirmed the diagnosis, and contrast enhancement with typical MRI characteristics made it possible to verify the hemangioma. When planning the surgical tactics CT angiography was performed, which clarified the localization and bloodstream architectonics of the hemangioma. Subsequently, a successful embolization of the "feeding" artery was performed in the X-ray operating room. However, two weeks later the patient returned with an increase in the clinical picture of hydropericardium. Surgical removal of the hemangioma was performed with a marked improvement in the patient's condition.Discussion. When excluding inflammatory changes in the myocardium and pericardium, valvular pathology of the heart in patients with hydropericardium, we must always remember the rarer cause -tumors in the pericardial cavity, in particular, hemangioma. Modern CT and MRI allow not only making the correct diagnosis, but also providing the surgeon with comprehensive information, sufficient to make a decision on the extent of the operation. The severity of the patient's condition and the presence of much comorbidity did not complicate neither the study nor the evaluation of the result.Conclusion. The clinical case not only illustrates the complex approach to diagnosing pericardial hemangioma, but also perfectly emphasizes that with severe pericardial effusion, one should remember about the rare causes of its occurrence that require radical surgical treatment.