Titanium and its alloys may be processed via additive manufacturing techniques such as Electron Beam Melting (EBM). This field is receiving increased attention from various manufacturing sectors including the medical devices sector. While the economic and engineering potential of EBM for the manufacture of musculo-skeletal implants is clear, the impact on the biocompatibility of the materials has been less investigated. In this study, effects of build orientation induced surface modifications on the in-vitro biocompatibility of the EBM Ti6Al4V alloy were investigated. The study assessed the suitability of three different Ti6Al4V surfaces produced via the EBM process as matrices for proliferation and attachment of mouse fibroblast L929 cells. The three different surface roughnesses were obtained by orienting the builds in vertical, inclined (55°) and horizontal orientations in the EBM build chamber. The mouse fibroblasts were cultured in vitro on the Ti6Al4V alloy discs with three different surface finishes. Cell viability studies, fluorescent microscopy as well as SEM micrographs were used to assess the L929 cell attachment and proliferation. After 2 and 8 days of incubation there was a higher vitality and proliferation of L929 cells on the vertical and inclined surfaces (Ra = 38 ?m and 46 ?m respectively) than on the horizontal surfaces (Ra = 18 ?m). On the vertical and inclined samples cells spread over a wider area of the surface. The results showed that that the implants produced by EBM meet basic biocompatibility requirements and also showed that build orientation of titanium during EBM can produce surfaces with different characteristics and these can affect cell growth.