The authors report a case of a child, 10 years old with a primary rhabdomyosarcoma of the heart that obstructed both caval veins. The clinical picture that lasted just three months before the admission was characterized by persistent fever, accentuated loss of weight and a very deteriorated general aspect. We emphasize the clinical aspects and other subsidiary elements that easily allowed to make the precise diagnosis in life as well as the therapeutic measures and follow up, besides a review of the literature, where it was confirmed the rarity of this pathological entity.