Mevalonic aciduria because of mutations of the gene for mevalonate kinase causes limited synthesis of isoprenoids, the effects of which are widespread. The outcome for affected children is poor. A child with severe multisystem manifestations underwent orthotopic liver transplantation at age 50 months for the indication of end-stage liver disease. This procedure corrected liver function and eliminated portal hypertension, and the patient showed substantial improvement in neurological function. However, autoinflammatory episodes continued unabated until hematopoietic stem cell transplantation was performed at 80 months. Through this complex therapy, the patient now enjoys a high quality of life without significant disability.