<p>Additive manufacturing is one of the emerging technologies for the manufacturing industries such as automobile, construction, medical and food industries. It avoids error and unnecessary waste as an alternative way of creating complicated or complex design of parts. It also allows greater versatility in customization and development of parts. Fused filament fabrication (FFF), an extrusion-based and a cost-effective additive manufacturing technique is studied in the present work. This work focuses on investigating the sound effects of process parameters of build orientation, printing speed and layer thickness on tensile strength, flexural strength, hardness and impact energy of poly-ethylene-terephthalate-glycol (PETG) samples fabricated through a FFF printer. Using the Taguchi method, the experimental design for this research is developed and the samples are fabricated according to the ASTM standards. On-edge build orientation exhibits better mechanical properties rather than flat and upright orientations because of the anisotropic behavior of the FFF printed parts. The mechanical properties are majorly affected by the build orientation, while layer thickness and printing speed have shown a little effect. In addition, the optimal process parameters settings for multi-responses obtained from the Grey relational grade are the build orientation of on-edge, printing speed of 20&#xa0;mm/s and layer thickness of 0.21&#xa0;mm, respectively. Finally, water absorption impact is also studied and discussed.</p> Graphical abstract