A 49-year-old male patient with a carcinoma of the right pyriform sinus had a whole-body bone scan and gamma camera based F-18 FDG-PET for staging. Tc-99m MDP bone scan depicted diffus increased uptake in the left femur due to chronic osteomyelitis but no skeletal metasis. F-18-FDG-PET revealed increased focal bone uptake and uptake in the draining sinus due to chronic osteomyeltis in addition to visualization of the right pyniform sinus carcinoma and righr neck nodal uptake. Fluorine-18 fluorodeoxyglucose-positron emission tomography is significantly more accurate than the bone scan in pinpointing chronic osteomyelitis focus and draining soft tissue infection.(Korean J Nucl Med 2002;36;143-145)