Rapid Prototyping technology based on Fused Deposition Modeling (FDM) is widely used as Additive Manufacturing or 3D printing technology. This technology works by heating the filament-shaped material and then producing the extrusion which then forms layer by layer. Filament Polyethlene Terephtalate-Glycol (PETG) is one type of polymer that is often used in 3D printing technology. The objective of this research is to determine the optimal process parameters and the best combination of optimal level of process parameters for the 3D printing process of PETG product using Taguchi method. The experimental design being used in this research was the orthogonal arrays of L9 (33) that has nine experiments with three process parameters used is nozzle temperature, extrusion width and feed rate with three level variations on each parameter (240oC, 245oC, 250oC, 0.3mm 0.35mm, 0.4mm, 80%, 90%, 100%). The responses in this research were dimension accuracy (w and T) and tensile strength of 3D printing PETG product, then data response result was analyzed using SNR and ANOVA. Based on the results of SNR and ANOVA analysis shows the most influencing of process parameters on the dimensional accuracy response was dominated by nozzle temperature, and the tensile strength response was influenced by feed rate followed by extrusion width. Based on the confirmation experiment for tensile strength response using the combination of optimal process parameter levels generated from the Taguchi Method is nozzle temperature 250 oC, extrusion width 0.3 mm, and feed rate 90% showed results that significantly improved the tensile strength of PETG products with a tensile stress value of 20.79 MPa at a 95% confidence interval (CI).