This is a case report of a 44-year-old male living in Teresópolis, RJ, Brazil, probably poisoned by contact with a Lonomia caterpillar, who presented hemolytic anemia, decreased platelet count and acute renal insufficiency. Lonomia erucism diagnosis was established by anamnesis and clinical and laboratory manifestations. Therapeutic measures consisting of hemotransfusion and hemodialysis were successful. Physiopathologic and clinical features of erucism by Lonomia are discussed.