Tumours originating from cardiac tissues are rarely encountered during childhood, and fortunately most of these tumours are benign in nature. Inflammatory myofibroblastic tumour, which has unique clinical, pathological, and molecular characteristics, is a relatively new entity compared with previously mentioned tumoural processes originating from the heart. Most of the cardiac intima-media thickness patients are in the age group of 4 months to 17 years. This rarely seen tumoural process has not been subject of any specific research and the prognosis is not well known. Here we present the case of a 3-month-old child who was admitted to our outpatient clinic with massive pericardial effusion and who has shown excellent progress after surgical resection of over 1 year.