Thirty cases of human kala-azar were diagnosed by iliac crest biopsy and myeloculture. Histological analysis of 12 patients showed diffuse thickening of reticulin fibers. To the best of our knowledge, this is the third report describing secondary bone marrow fibrosis (myelofibrosis-like) associated with kala-azar. Patients with positive bone marrow fibrosis (pbmf = 12) were compared to patients without detectable bone marrow fibrosis (wbmf = 18). There were no significant differences in clinical and blood parameters following treatment. All patients showed regression of hepatosplenomegaly.Our findings suggest that associated bone marrow fibrosis is transient and did not interfere in the evolution of treated patients