Introduction: The success of dental implants depends primarily on the primary implant stability and the bone density so that predictable osseointegration can be achieved. To achieve the desired results, systematic preoperative planning for implant placement is required. The sole aim of the study was to assess the reliability of preoperative bone density of mandibular posterior region for implant placement using computerized tomography-derived bone densities in Hounsfield units (HU). Materials and methods: A total of 200 patients with 352 implant sites between 2014 and 2017 were assessed for the posterior mandibular area using cone-beam computed tomography (CBCT). Evaluation was done by two experienced observers independently. Results: The mean bone density of males was 690.5 ± 104.12 HU and in females, it was 580.20 ± 120.2 HU. Overall, 21% of sites were of low bone density, 39.5% were of intermediate density, and 39.4% were of high density. Receiver operating characteristic (ROC) analysis presented that the CBCT intensity values had a high predictive power for predicting both highdensity sites and intermediate-density sites. Conclusion: We can say from our results that, for predicting the bone densities in posterior mandible for determining implant sites, so as to achieve best osseointegration, CBCT values can be reliably used. Clinical significance: It has been proved that bone density and implant stability are dependent on each other and osseointegration is important for the success of treatment. With advancements in dentistry and introduction of CBCT, treatment planning and prediction of appropriate implant sites could be made easy and more predictable. Thus, we can say that CBCT can be considered an alternative diagnostic tool for the bone density evaluation during treatment planning for implant placement.