By way of bronchoscopy and bronchoalveolar lavage, intrapulmonary steady-state concentrations of micafungin administered at 150 mg daily to 15 healthy volunteers were determined at 4, 12, and 24 h after the third dose. The micafungin disposition was predominantly intracellular, with approximately 106% penetration into alveolar macrophages and 5% penetration into epithelial lining fluid.