With increasing structural and functional applications of 3D printed materials, their mechanical performance is highly demanded. So far, stress-And strain-based experiments have been used to characterize the mechanical properties of fused deposition modeled (FDM) samples. In this work, a fracture-mechanics-based methodology was developed to characterize the interlayer adhesion of FDM 3D printed materials. Double cantilever beam (DCB) specimens were designed and printed with a precrack set at the interface of the layers. The DCB samples were tested in mode I loading and the load displacement curves were obtained. Critical stress intensity factor was found using the DCB loading data coupled with a finite element model. The critical strain energy release rate, Gc was also calculated using the finite element model data and the elastic properties, obtained by the tensile test of FDM 3D printed samples. The results of this work demonstrates a methodology that can be implemented to measure the interlayer fracture resistance of FDM printed materials.