Purulent pericarditis (PP) is rare disease, and if left untreated, it is associated with very high mortality, nearly 100%. A considerable clinical problem due to PP is a very high probability of developing constrictive pericarditis (CP). Pericardial drainage is essential in the treatment of PP and should be performed urgently. The use of broad-spectrum antibiotic therapy is equally important. Unfortunately, fibrin deposits often create occulated spaces and reservoirs that reduce the penetration of antibiotics and their effectiveness. The rationale for the intrapericardial use of fibrinolytic drugs in PP is based on their ability to dissolve fibrin strands and collagen fibres, thus improving the penetration of antibiotics to the pericardial sac and lowering the risk of CP. The choice of the drug, as well as its dosage and the method of administration is still under debate. The authors of the article share their experiences and review current literature on this rare topic.