Osteomyelitis of the frontal bone, otherwise known as Pott's puffy tumour, is a rare complication of frontal sinusitis or direct injury to the frontal bone in adolescent age group. Potts Puffy tumor can be complicated with cortical vein thrombosis, epidural abscess, subdural empyema, and brain abscess. Venous drainage of the frontal sinus flowing through diplopic veins, which have communication with the dural venous plexus is the cause of venous thrombosis. Through this venous system septic thrombi can potentially evolve and propagate from foci within the frontal sinus. We aimed to emphasize in this case report that Pott's puffy tumour should be considered in the differential diagnosis in a patient with swelling on the forehead, due to its high mortality rate of about 17%.