<p>Polylactic acid (PLA) is a biodegradable polymer widely employed in fused deposition modeling (FDM) 3D printing due to its sustainability and ease of processing from renewable resources. Despite its advantages, PLA exhibits inherent brittleness and anisotropic mechanical behavior, limiting its use in load-bearing applications. This study aims to address how the key 3D printing parameters—layer height, infill density, infill pattern, and raster orientation—can be optimized to enhance the mechanical performance of FDM-printed PLA components. Using the robust Taguchi design of experiments methodology, PLA specimens were systematically fabricated varying these parameters across multiple levels. Mechanical properties, including tensile strength, compressive strength, and hardness, were quantitatively assessed using standardized testing protocols complemented by microstructural analysis. Results demonstrate that a combination of a 0.1 mm layer height, 100% infill density, line infill pattern, and 0° raster orientation yields superior mechanical properties, achieving tensile strength of 52.7 MPa, compressive strength of 61.38 MPa, and hardness of 82.17 D. Statistical analysis revealed infill density as the dominant factor influencing strength, while raster orientation showed limited direct effect. Microstructural investigations supported these findings by showing enhanced interlayer adhesion and reduced porosity under optimized conditions. This work contributes a comprehensive parameter optimization framework for sustainable, high-performance 3D-printed PLA components, advancing the reliability of additive manufacturing processes for engineering applications. The study lays a foundation for future research targeting real-time adaptive printing strategies and composite material integration.</p> Graphical Abstract <p></p>