Nasal polyps are soft, fleshy masses that can arise from the nasal mucosa. Histologically, there are different types of nasal polyps ranging from inflammatory to neoplastic. The most common type is the oedematous allergic nasal polyp, which is lined by thickened epithelium and contains eosinophils, plasma cells and lymphocytes in the submucosa. Chronic inflammatory polyps can develop from traumatized allergic polyps and contain submucosal fibrosis. Rarely, seromucinous polyps can occur due to glandular hyperplasia. Microscopic examination is important for classification and diagnosis of underlying conditions.