Electron beam melting (EBM) is gaining more interest due to its near-net-shape production and ability to process di cult to manufacture materials, such as titanium alloys. However, due to the poor surface quality of the EBM parts, nishing operations, such as machining, are required. The main issue in the nishing of the EBM parts is their directional properties that lead to different surface roughness values for different part orientations for the same employed machining parameters. In this study, EBM Ti6Al4V parts were subjected to heat treatment to suppress the effect of the part/layers' orientations effect during the nish milling process. Three different heat treatments were employed to the as-fabricated EBM Ti6Al4V parts. The ne lamellar microstructure was set as a target from the heat treatment due to its overall superior mechanical properties and also, to keep a fair comparison in the machining of the asfabricated and heat-treated EBM Ti6Al4V parts. The results of the heat treatments showed that the EBM Ti6Al4V parts heated at 600°C for 3 hours and then air-cooled exhibited the same ne lamellar microstructure and microhardness as that of the as-fabricated EBM parts. The other two heat treatments including heating at 950°C and 800°C for 2 hours followed by air cooling were not able to maintain the ne lamellar structure due to the increase in the width of the alpha grains. The as-fabricated and heattreated EBM Ti6Al4V parts were subjected to the milling operation by considering the three possible parts/layers orientation with respect to the tool feed directions. The milling results showed that the asfabricated parts showed up to a 27% difference in surface roughness for different part orientations. In contrast, the heat-treated parts showed uniform surface roughness for the three part orientations with a variation of 8%. Similarly, considerable differences were observed in the surface integrity and the machined surface microhardness (18%) of the as-fabricated EBM parts as compared to the heat-treated parts) 2%). The heat-treated parts showed more uniform and superior surface morphology across all the part orientations. This is because of the more uniform microstructure, less porosity, higher consolidation of the EBM layers, and elimination of the columnar grains in the case of the heat-treated parts as compared to the EBM parts. This study revealed that in the case of the heat-treated EBM part the effect of part orientation with respect to milling tool feed direction was almost removed.