Mucormycosis of the nose and paranasal sinuses is a rare invasive fungal infection, which often has a very fulminant course and characteristic clinical findings in immunosuppressed patients. Case report: A 20 y/o male patient underwent liver transplantation for treatment of Budd-Chiari syndrome in Shiraz transplant unit. He received whole liver from a deceased donor and the operation was difficult because of complete obstruction of hepatic veins. The patient received intravenous methylprednisolone (replaced with oral prednisolone after 3 days), tacrolimus and mycophenolate mofetil (MMF) for immunosuppression from the first day after the operation. The patient developed signs and symptoms of outflow obstruction of the transplanted liver which was treated successfully by angiographic intervention and discharged 29 days after the operation without any other complications. During 3 weeks after discharge, the patient mistakenly received 100 mg/day oral prednisolone in spite of 10 mg because of similarity in the shape of 5 and 50 mg prednisolone tablets. The patient developed unilateral face pain with high fever, purulent rhinorrhea and toothache and the diagnosis of unilateral fungal pansinusitis confirmed by biopsy. Treatment by intravenous amphotericin, reducing the dose of prednisolone, endoscopic surgical debridement and irrigation of the nose and involved sinuses with amphotericin was successful and the patient became completely asymptomatic after 1 month and in the last follow-up after 1 year. In conclusion, Sinus mucormycosis in a liver transplant patient is a rare and potentially lethal complication. Early diagnosis, aggressive treatment with amphotericin and endoscopic debridement and careful monitoring of the level of immunosuppressive drugs can be helpful in treating these patients and achieve favorable prognosis.