Complications of paranasal sinusitis constitute true surgical and medical emergencies. Whilst sinus complications can occur in apparently young healthy individuals, more often than not, there is some underlying cause such as the patient being immunosuppressed. Complications also occur more frequently in children than in adults. This may be due to dehiscences in the bone, relatively vascularity of bone or the thinness of bones, apart from children being more susceptible to infection. The most common complications of paranasal sinusitis are the orbital complications. Intracranial complications include meningitis, subdural empyema, intracerebral abscess, epidural abscess and rarely cavernous or superior sagittal sinus thrombosis. Other sinus related complications are mucoceles, pyoceles, osteomyelitis, cellulitis, barotrauma and dental complications. In most cases, diagnosis may be confirmed by a combination of a high index of clinical suspicion and MR or CT scanning. For patients with acute complicated sinusitis appropriate antimicrobial agents would include azithromycin, clarithromycin, amox-clav., cefixime, cefdoxime, cefprozil, cefuroxime, clindamycin, ceftibuten, loracarbef, and sparfloxacin. Surgery needs to be done for the resultant condition when indicated (such as abscesses or mucoceles), and the offending sinuses must be cleared (endoscopically or via an external approach) to prevent recurrences.