Since its first synthesis in the year 2004, graphene was characterized with exceptional properties such as high Youngs modulus of 1 TPa, very high electrical and thermal conductivity as well as an intrinsic strength of 130 GPa. Due to these properties graphene is very attractive to be applied as additive in metal matrix composites (MMCs). In recent years a lot of studies were carried out applying different manufacturing approaches. Characterization of the composites’ mechanical properties lead to varying success since most authors found improvements of mechanical properties while others observed detrimental effects through the addition of graphene. In the current study three different graphene sources were applied in powder metallurgical preparation of aluminum graphene composites. Two of them were commercially available graphene nano platelets (GNPs) and the third one was self-synthesized graphene. Different graphene contents of 0.25%, 0.5% and 1.0% were applied. Composites were manufactured via a powder mechanical route consisting of ultrasonic graphene exfoliation, mechanical mixing, disc milling, cold compaction and extrusion. The mechanical properties by means of micro hardness, tensile as well as compressive testing were characterized in dependence of the graphene source. Results revealed no significant improvement or even decreasing mechanical properties for one of the commercial GNPs, while for the second commercial graphene improvements of up to 16% in TYS, 25% in UTS as well as up to 15% in CYS and 20% in micro hardness were observed. For the self-synthesized graphene an increase in TYS of 27%, in UTS of 25%, 31% in CYS as well as 23% in micro hardness were observed.