The author studied the value of therapeutic test for the diagnosis and treatment of kala-azar in children by comparing two groups of patients. The identification of Leishmania donovani in smears of bone marrow confirmed the diagnosis in all fifty seven patients of the control group. In another group with sixteen children, the diagnosis was based on the successfull response to the treatment with meglumine antimonate. In none of the patients of the second group the protozoa was identified and the decision to give the specific treatment was based on epidemiological, clinical, biochemical and hematological criteria for the disease. Statistical analysis was performed by Student t test to compare clinical, biochemical and hematological variables between the groups. None of the differences between the groups was satistically significant, suggesting that the therapeutic test was valid, and all patients who received treatment had kala-azar.