Sensory disturbances such as anesthesia, hypoesthesia, hyperesthesia, and paresthesia may be present in the oral cavity, stemming from many local and systemic factors. Paresthesia of the inferior alveolar nerve is quite rare because of the unique anatomy of this nerve. Among other effects, periapical lesions can damage the nerve, resulting in paresthesia of its innervated area. Only a few cases of paresthesia caused by these lesions are reported in the literature. In this report we present a case of paresthesia of the right inferior alveolar nerve; discuss the anatomy, pathobiology, and etiology; and suggest that a periapical lesion affecting the lower right second molar (No. 31) may have been the cause. The routine x-rays (intraoral and panorex) and the axial and cross-sectional tomographs of the mandible by means of computed tomography contribute to making this case a good example of nerve injury.