Titanium is commonly used in biomedical applications because it is dominant in many properties such as good biocompatibility, high corrosive resistance, high specific strength and nonmagnetic property. Nowadays, fabricating titanium devices or orthopaedic parts by selective laser melting (SLM) gains interest because of its advantages over conventional methods such as casting, or milling. The laser power is one of the factors that affects the mechanical properties during SLM process. The aim of this study was to examine the effect of the various laser powers on  tensile strength and microstructure of  Ti-6Al-4V ELI. The Ti-6Al-4V ELI alloy samples were printed in dumbbell shape by SLM machine (Trumpf/TruPrint 1000, Germany) with 3 laser powers (75,100 and 125 W) ,6 samples for each group. All samples were performed under tensile test with universal testing machine and data were analyzed with one way ANOVA and Tukey’s post-hoc post hoc tests (α=0.05). The microstructure was analyzed by optical microscope and mode of failure was observed by SEM. The results showed that the laser power 100 W with spot size 30 µm, scanning speed 600 mm/s, layer thickness 30 µm (fixed parameters) was suitable to achieve the highest tensile strength compared to the other 2 groups. Mode of failure after tensile testing in group of laser power 75 and 100 W showed in both ductile and brittle fracture. The group of laser power 125 W is predominantly brittle fracture.