Additive manufacturing, particularly Fused Deposition Modeling (FDM), has become a widely adopted technique in prototyping and small-series production. This is primarily due to its high flexibility and cost-effectiveness. However, ensuring dimensional accuracy remains a significant challenge, especially for functional components with tight tolerances. The aim of this study is to investigate the effect of two fundamental FDM parameters, layer height and print speed, on geometric accuracy. Nine configurations were tested by combining three-layer heights (0.1 mm, 0.2 mm, 0.3 mm) with three print speeds (40 mm/s, 60 mm/s, 80 mm/s). The test specimens were printed using an Ultimaker S7 printer with PLA Extrafill filament and subsequently remeasured using a 7-axis Hexagon Absolute Arm coordinate measuring arm. Each part was evaluated at seventeen predefined geometric features, resulting in a total of 153 measurement data points. Deviations were analyzed in comparison with the nominal CAD model values. The results indicate that the combination of 0.2 mm layer height and 60 mm/s print speed (L2S2) yielded the smallest deviations and the most consistent accuracy. Undersizing was typically observed for holes located in the XY-plane, while features along the Z-axis exhibited greater variation. The findings highlight the necessity of coordinated parameter optimization to improve dimensional accuracy.