<p>The build orientation in selective laser melting (SLM) controls the grain texture and phase distribution, which have a significant influence on the mechanical properties of Ti-6Al-4V, and has been extensively investigated in the literature. However, the dimensional limitations of parts produced by this method make it necessary to assemble smaller components to fabricate larger structures. Such assembly is achievable only through a restricted set of techniques, with laser welding being a primary option. The present study experimentally examines how both the build orientation and the assembly direction together influence the physical and microstructural characteristics of laser-welded Ti-6Al-4V components fabricated by SLM. It is found that the build orientation primarily influences the characteristics of the heat-affected zone (HAZ), where notable changes in microstructure and phase distribution occur. This study also demonstrates that accurate evaluation of the build orientation effect requires high-quality and defect-free laser welds. The presence of a predominantly brittle martensitic structure, along with large voids in the weld zone, adversely affected the mechanical performance of the specimens during testing, causing premature failure before the build orientation could exert a measurable influence. According to the results, the sample with a horizontal build orientation and alignment parallel to the weld direction exhibited increased strain and more predictable mechanical failure due to the presence of a partial martensitic phase alongside α and β phases within the HAZ. The highest weld strength was detected in the vertical specimen with an ultimate tensile strength of 419&#xa0;MPa and a strain of 0.5%, compared to the base metal strength of 913&#xa0;MPa and a strain of 5.1% in the corresponding sample.</p>