The basis for ancillary therapy of sinusitis derives from anecdotal accounts and personal beliefs rather than definitive data. The recent appreciation that noninfectious inflammatory causes predispose to infectious sinusitis has stimulated renewed interest in developing and documenting efficacious ancillary therapies that could supplement or abrogate antibiotic use. Ancillary therapies of sinusitis could be directed toward (1) preventing viral upper respiratory tract infections (immunizations, virucidal-impregnated tissues, and proper hand-washing techniques); (2) blocking rhinoviral replication and suppressing mediator release with supraphysiologic nasal hyperthermia, although contradictory studies exist with regard to efficacy; (3) promoting sinus and nasal ventilation with both topical and oral alpha-agonists and exercise; (4) improving mucociliary clearance by reducing mucus viscosity and elasticity with saline solution irrigation, mucoregulators (N-acetylcysteine, S-carboxymethylcysteine, and iodinated glycerol), and ciliary stimulants (adenosine triphosphate); and (5) suppressing/modulating cellular inflammation (eosinophilic, basophilic, and neutrophilic) with topical nasal corticosteroid sprays and mediator antagonists. Recommendations are forwarded for future investigations of promising nonantibiotic ancillary therapies of chronic sinusitis.