Introduction: Right-sided infective endocarditis, represents from 5% to 10% of infective endocarditis in adults, which is less frequent in children. Case Series: Case 1: A 12 year-old girl with fever and a history a left hip injury due to a fall. She developed breathing difficulties, shock, bilateral pneumonia, and cellulitis in the left hip. The blood cultures were positive for methicillin resistant Staphylococcus aureus (MRSA), as such that the echocardiogram showed growth in the tricuspid valve. Due to persistent bicytopenia, a bone marrow aspirate was performed, with acute lymphocytic leukaemia being diagnosed. She received vancomycin for six weeks and chemotherapy was subsequently started. Case 2: A 5 year-old girl, with fever, breathing difficulties, a leukemoid reaction, and bicytopenia, developed shock with bilateral pneumonia, and hepato-splenomegaly, as well as positive blood cultures for MRSA. The echocardiogram showed growth in the tricuspid valve, and the bone marrow aspirate performed helped diagnose an acute lymphocytic leukaemia. The patient died.