We describe the first case of Aspergillus myositis caused by Aspergillus flavus in a liver transplant patient. The patient was a 43-year-old man who underwent liver transplantation because of end-stage hepatic cirrhosis. He experienced pain in his left calf two months after the operation. Nodules with weakness, swelling, and flaring were found in the calf two wk later. Color ultrasonic examination showed uneven resonance in the left gastrocnemius. Needle aspiration and biopsy of the muscle revealed septate hyphae consistent with Aspergillus species and focal necrosis of the muscle cells with inflammatory cell infiltration. A culture subsequently yielded A. flavus, confirming histopathologic diagnosis. Sequencing of the internal transcribed spacer region confirmed the morphologic identification. The patient was first given itraconazole 0.2 g twice daily for one wk and was then switched to terbinafine 0.25 g once a day. A three-month regimen of terbinafine therapy cured the infection, though the cultured fungus showed resistance to a number of antifungal agents. Aspergillus, a genus of ubiquitous molds, may cause invasive and even fatal disease in immunosuppressed patients.