Recent studies have indicated the existence of an active cellular defence in the secretion on the tonsillar surface. This defence seems to consist partly of physiologically active neutrophils and is present in health and during disease. The present study was undertaken to examine the migration of these neutrophils to the secretion on the mucosal surface. Tonsils from 6 patients with acute tonsillitis and 5 patients with snoring problems were removed and sectioned. Sections were stained immunohistochemically against CD15 to visualise neutrophils. Other sections were stained with acridine orange to detect bacteria. Clusters of neutrophils were frequently seen in tonsils both from patients with acute tonsillitis and from snorers. They were observed to be accumulated within the tonsillar epithelial layer. Streaks of neutrophils could be observed running not only from vessels mainly near or within the epithelium to the epithelial surface, but also from vessels far from the epithelium through the extrafollicular areas to the epithelial surface. Bacteria were not present in the epithelium. We consider that the findings indicate an active physiological migration of neutrophils to the tonsillar surface.