Additive manufacturing technologies are used to produce three-dimensional object. Fused Deposition Modeling (FDM) is one of the 3D printing processes. The notable advantage of 3D printing is to develop actual parts directly. But it has a limitation for printing long parts due to the bed size. It can be overcome apply secondary using joining of polymers. Friction Stir Welding (FSW) is classified as solid-state welding widely preferred in automobiles and aerospace products. It has significant advantages of no melting, reduced heat affected zone and environmentally friendly aspect. In this work, 3D printed polymer specimen is joined using FSW process. Polylactic Acid (PLA) is used as work piece material. Process parameters considered are tool pin profile (circular, hexagonal and square), tool rotational speed and tool feed. Response parameters considered are tensile strength and bending strength. The result of the experiment is understood that better combination of process parameters such as tool low level value of rotational speed and medium level of tool travel speed with hexagon pin profile are significantly influenced the performance in terms of tensile strength and bending strength.