This study aims to systematically experimental investigate the influence of infill-patterns (IPs) on specific mechanical responses of parts fabricated by fused deposition modeling (FDM). A poly-lactic-acid (PLA) feedstock filament is utilized in the manufacturing process. Furthermore, six types of infill-patterns (deposition angle), namely full honeycomb, rectilinear, triangular, fast honeycomb, grid, and wiggle, are designed and printed. In order to determine the mechanical properties of manufactured parts, tensile tests are carried out. The mechanical properties such as extension, stress, elongation, energy, and Young's modulus are considered as objective functions. As a result, there is a direct correlation between mechanical properties and infill patterns. Thus, it is essential to select the best infill-pattern in terms of their applications, giving sufficient strength without overdoing time and cost. Based on the results, a triangular infill-pattern has a maximum value of ultimate tensile strength and E-module (15.4 and 534 MPa, respectively). On the other hand, the wiggle pattern is more flexible.