The capability of producing injection tool inserts using an additive manufacturing (AM) technology was investigated. Using electron beam melting (EBM), the restriction of drilling straight cooling channels could be eliminated and freeform channels with sufficient powder removal were achieved. EBM parameters and the design of the cooling channels strongly influence the sintering degree of the powder trapped in the channels and thus the ease of the powder removal. Despite the low heat conductivity of the new inserts made from Ti6Al4V, the cooling performance was the same as for the conventional inserts. However, the use of Ti6Al4V is advantageous, since the expanding agent used in injection molding is very corrosive.