Normally implants are installed above mandibular canal. In some cases, the alveolar bone height is not adequate for fixtures with optimal length. An installation lateral or medial to the mandibular canal may be an alternative to ridge augmentation or nerve lateralization. To the best of our knowledge, the feasibility of installing fixtures lateral or medial to the mandibular canal in Thais has not been studied. Objectives: Distance from buccal border of mandible to buccal side of mandibular canal (BB-MC) and distance from lingual border of mandible to lingual side of mandibular canal (LB-MC) were measured to the nearest 0.01 mm on the reformatted cross-sectional images from cone beam computed tomography. Methods: The total images on 65 mandibular molar areas were from 30 Thai implant patients. A second measurement was performed to examine measurement precision which was calculated by Dahlberg's formula. Results: The measurement precision was found to be 0.27 mm. The mean distances BB-MC and LB-MC were 4.71±1.19 and 3.51±1.12 mm, respectively. 57% of the 65 areas showed a distance BB-MC of at least 4.5 mm whereas 17% of the 65 areas revealed a distance LB-MC of at least 4.5 mm. Conclusion: Installing a fixture lateral to mandibular canal might be more probable than medial to the canal, provided the fixture inclination was acceptable.