Nowadays, to solve the problems of implants, damaged bone is repaired using biocompatible scaffolds. In this research, PCL/PLA/ZnO scaffolds were fabricated by melt extrusion 3D printing. Polycaprolactone is one of the well-known biocompatible and bioactive materials for bone scaffolds, but it is hydrophobic and has a low degradation rate. Therefore, polylactic acid was used to increase degradability and hydrophilicity. Also, zinc oxide was used to increase mechanical and biological properties. For this purpose, PCL or PCL containing 1, 2 and 3 wt% ZnO nanoparticles and PLA were printed layer by layer. The morphology and mechanical properties were studied by SEM images and compression test, respectively. The SEM images showed that the printed scaffolds had a regular structure with a pore size between 300 and 400 micrometers. Adding PLA and ZnO to PCL scaffolds significantly improves mechanical performance and PCL/PLA/ZnO composites have a favorable compressive strength for bone tissue engineering applications. By adding PLA to PCL, the stiffness increased from 52 MPa to 214 MPa. The addition of zinc oxide nanoparticles up to 3% by weight has increased the stiffness from 214 MPa to 273.48 MPa in the PCL/PLA/3%ZnO sample. Results have demonstrated that PCL/PLA/ZnO scaffolds prepared by melt extrusion 3D printers are a highly promising solution for bone tissue engineering.