The relationship between allergic rhinitis and sinusitis is reviewed with regard to seasonal as well as perennial and fungal sinusitis. There seems to be some association between allergic processes in the nose and inflammation in the sinus mucosa but the available data are, to some extent, contradictory. Thus, the causative role of allergy in sinusitis is not clear. Prospective studies to further elucidate the influence of allergic inflammation in the pathogenesis of sinusitis are highly warranted.