Tuberculosis and myelofibrosis are reported in conjunction often enough to raise the possibility that a relationship exists between the 2 entities. However, whether tuberculosis stimulates a secondary fibrotic reaction or develops in patients who have preexisting myeloproliferative disorders is not clear. We describe the case of a 28-year-old man in whom myelofibrosis disappeared completely after administration of antituberculous treatment, which suggests that a causal relationship exists between the 2 disease entities.