In the present study Ni particles were incorporated in 5083 Al alloy by friction stir processing (FSP) to fabricate metal particle reinforced composite. A conventional cylindrical tool was first used for FSP and several processing parameters (rotational and traverse speeds) were exploredto get a defect free stir zone and uniform distribution of the particles. The effect of tool geometry was also studied by using another tool having special features on the pin and the shoulder. A tool rotation speed of 1200. rpm and traverse speed of 0.4. mm/s were found to be optimum for obtaining a defect free stir zone. However, the distribution of Ni particles was inhomogeneous for all the parameters used with the plain cylindrical tool irrespective of defective or a sound stir zone. The tool with the special features, threads on the pin and spiral grooves on the shoulder, was found to be very effective in both producing a sound stir zone and dispersing the Ni particles. It was also found that ball milled fine particles were dispersed more uniformly in the stir zone compared to the as-received coarse particles. FSP also refined the grain size of the aluminium matrix from 25μm to 3μm. The microstructure was characterised by equiaxed fine grains with a high fraction of high angle grain boundaries and a narrow grain size distribution. The effect of the particle incorporation on the mechanical properties of the alloy was also investigated. The strength increased significantly compared to the base alloy and more importantly a high amount of ductility was also achieved in the composite. © 2015 Elsevier Ltd.