Cone beam computerized tomography (CBCT) has been wildly used in various disciplines of dentistry, including endodontic task of investigating for vertical root fracture (VRF).  Previously, CBCT systems were dominated by medium to large field of view (FOV).  As for high cost and large machine size, newly designed CBCT systems started to develop by combining them with digital panoramic radiography into one machine.  These new models of CBCT system was called hybrid CBCTs.  The aim of this study is to compare the difference in VRF detection performance using various FOV in hybrid CBCT and conventional CBCT units.  Forty permanent mandibular premolar teeth were endodontically prepared and individually inserted into a dry human mandible.  All teeth were scanned before and after induction of VRF using 4x4 and 8x8 cm FOVs. One observer randomly evaluated all radiographic datasets.  Ten percent of samples were randomly selected for repeated observation with 2 weeks separation.  The area under receiver operating characteristic curve (AUC) for hybrid CBCT and conventional CBCT are 0.835 and 8.847, respectively.  Slightly better detection ability with conventioal CBCT is revealed.  The smaller FOV and voxel sizes, the better VRF detection are observed in both machines.  In conclusion, detection of VRF with hybrid CBCT might not different from that in conventional CBCT system, and smaller FOV might associates with higher detection ability.