In the current study, the effect of sample dimensions and process parameters (beam current, scan speed, offset focus and scan length) of EBM system on microstructure of the EBM built Ti-6Al-4V has been investigated. In general, it can be observed that the microstructures of EBM built Ti-6Al- 4V consist of columnar grains of prior β phase. Inside the columnar grain typical (α+β) structures namely Widmanst?tten α platelets with rod like β phase formed on the interfaces of the fine α grains has been observed. Grain boundary α layer is found to be formed along grain boundary of prior β columnar grain. With increasing thickness of the test slab, beam energy density and scanning length, the diameter of prior β columnar grain increases and they follow the build direction. The columnar grain diameter also decreases with increase in height. With increasing thickness and beam energy density α platelets get coarser.