Rifampin is a bactericidal antibiotic used primarily in the treatment of tuberculosis. The adverse effects of rifampin, though few, include dermatologic, gastrointestinal, and hepatic manifestations. Occasionally it produces a flu-like syndrome, interstitial nephritis, hemolytic anemia, and thrombocytopenia. These manifestations usually appear in patients who take the drug intermittently. We experienced a 13 year-old girl who developed thrombocytopenia during rifampin administration of daily dosage, therefore we report a brief review with the related literatures.