An 8-year-old boy, with fibular agenesis, tibial campomelia, and oligosyndactyly (FATCO syndrome), had been operated on for reconstruction 3 weeks prior at another hospital. He was admitted to our hospital because of right leg pain and purulent exudates from the surgical wound site for one week. Physical examination revealed purulent material at the surgical wound on the right leg. Radiological examination confirmed the clinical diagnosis as osteomyelitis. Clinical findings did not improve with empirical antibacterial therapy. A microbiological examination yielded a filamentous fungus from three different specimens that was identified as Aspergillus flavus. The patient was treated successfully with oral itraconazole for 6 weeks. In conclusion, invasive Aspergillus infections can affect immunocompetent adults and children. Trauma and surgical intervention can also be a risk factor for immunocompetent individuals. In addition to surgery, itraconazole can be a good choice in the treatment of Aspergillus osteomyelitis, especially in children.