© 2023 Gazi Universitesi Muhendislik-Mimarlik. All rights reserved.In the last century, polymer materials such as polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), and polyethylene terephthalate glycol (PET-G) are widely used in many industrial fields due to being light, cheap, sustainable, and providing enough strength for engineering applications. Although plastic materials are mostly manufactured by the extrusion method, the 3D printing method is also taking the attention of researchers in the last decade because of its advantages over traditional methods. When the literature efforts about 3D printed polymers are examined, it can be seen that they are mostly focused on mechanical performance-determining processes such as tensile, compression, and three-point bending. In this performance, the effect on layer height on the drop-weight impact behavior of 3D printed PET-G samples with fused deposition modelling (FDM) was examined at the various ambient temperature of 20℃, 40℃, and 60℃ besides determining the hardness and tensile strength of the specimens. The results show that a maximum average hardness value of 69,4 Shore D was obtained at the specimen with layer height of 0,4 mm. It was determined that as the layer height value increased, the hardness values of the structures increased and the tensile strength values decreased. Besides, it can be stated that the layer height plays a more important role in the energy absorption amounts of the parts than the test temperature. Lastly, according to macroscopic and microscopic detections, no cracks were observed in the samples with a layer height of 0.4 mm, while it was determined that cracks were formed extending from the center to the corners in the samples with a layer height of 0.1 mm and 0.2 mm.