Acute bacterial rhinosinusitis (ABRS) is a well-recognised and common problem confronting many primary care physicians but the abuse of antibiotic therapy for viral aetiologies of ABRS has lead to widespread bacterial resistance. The once easily-eradicated pathogens have developed many mechanisms to resist antimicrobial therapies. The most common pathogens Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis are still found in cultures of sinus cavities but Staphylococcus and possibly some anaerobes play an important role in the development of the chronic stage of rhinosinusitis. The choice of antibiotic therapy for both ABRS and chronic rhinosinusitis (CRS) are reviewed, along with considerations for ancillary therapy. Note is made of the role of chemical mediators in the inflammatory stage possible strategies to reduce this problem. Allergic fungal rhinosinusitis results from a hypersensitivity reaction to demetiaceous fungi. Cure of the effects of rhinosinusitis depends on the establishment of a healthy sinus cycle.