Background and Aim: The aim of this study were to assess the axial inclination of upper incisor and to evaluate the relationship between the angular measurement data (incisor long axis to maxillary plane and occlusal plane) and the third-order angle according to Andrews’ description by using the device—the tooth inclination protractor (TIP). The sample comprised 60 subjects of south Indian origin between 15- 30 years of age (regardless of skeletal and dental relationships) seeking orthodontic treatment at the department of orthodontics, K.V.G. Dental college Hospital, Sullia and other dental colleges, with lateral cephalometric radiographs and dental casts. The scores were related to traditionally determined inclinations for the upper incisor to occlusal plane obtained from cephalometric radiographic analysis. The following angles were measured on the radiographs: maxillary incisors to maxillary plane and occlusal plane. Measurements were also made with the TIP: maxillary incisor to occlusal plane. There were statistically significant systematic differences between the TIP and the radiographic assessments. The following differences were found. The TIP over scored the lateral cephalometrically determined maxillary incisor inclination by 14.52°. The TIP was shown to be a simple, inexpensive, reliable, and valid method of assessing incisor inclination.