We carried out a case series detailing their presentations, clinical courses and outcomes, and discussed the identification and management of complications of bacterial sinusitis. Methods Three cases of complicated sinusitis from September 2018 were selected from the emergency department admissions record. Their medical records including lab results and imaging reports were reviewed and comparisons between the three cases were made. Results The three cases, all male, were aged 14, 11 and 11. All three had had preceding symptoms of coryza, pyrexia and headache. One developed neck pain and vomiting and was initially thought to have meningitis. CT brain revealed left sided sinusitis with an extradural abscess. The other two patients were initially treated as orbital cellulitis. One was transferred from a peripheral hospital, where he had presented with eye swelling and pain, after he developed diplopia and frontal bone swelling. CT showed pansinusitis with a right sided frontal osteomyelitis and a subperiosteal collection in keeping with Pott's puffy tumour. The other presented with eye swelling and pain; CT showed pansinusitis with an extradural empyema. All three patients had markedly raised inflammatory markers on presentation. All required prolonged courses of IV antibiotics. All three had neurosurgery and ENT involvement, the cases of orbital cellulitis had daily ophthalmology reviews. Two had FESS procedures with drainage of their abscess. Conclusion These three cases demonstrate the potential for bacterial sinusitis to cause serious complications. It is important for the clinician to bear these complications in mind when evaluating the child with rhinosinusitis and to consider imaging when there is a clinical suspicion. Speciality involvement is vital in the management of complicated sinusitis. There is a role for the development of a national clinical guideline pertaining to the management of bacterial sinusitis in the paediatric population.