One hundred cases of chronic sinusitis, aged 6 to 15, were examined and histopathological study of the mucosa of the sinuses was made. Edema of the mucosa was much more remarkable than in adults, probally due to the exudative diathesis, which is common in children. No remarkable vascular change in lamina propria was observed and this was thought to be responsible for the spontaneous healing of the disease in children.