This article presents a diagnostic protocol for nasal disease evaluation that provides consistent success in diagnosis of chronic cases. The protocol includes history, physical examination, blood clinical pathology assessment, radiographs, culture and sensitivity tests, rhinoscopy, histopathology, fungal serology, and allergy screening. The sequence of diagnostic procedures and their techniques are discussed, and rhinoscopic appearance of the normal nasal cavity is presented, along with findings of commonly seen nasal diseases, including neoplasia, mycotic rhinitis and sinusitis, foreign body obstruction, dental disease, allergic rhinitis, bacterial rhinitis, and idiopathic rhinitis. Rhinoscopy is a highly effective diagnostic technique with minimal morbidity and mortality that has virtually eliminated the need for exploratory rhinotomy.