A theoretical study for small Pt-p aggregates (p = 1-4) adsorbed on Ni(111) has been performed by following a model previously implemented for Ni/Ni(111) and Pt/Pt(111). Pt on Ni shows a relatively strong interaction with an adsorption energy close to the value for Pt on Pt. Our results suggest a very distorted overlayer for small Pt coverages favoring linear chains and predicting important relaxations particularly for planar configurations. We give also some insight concerning the changes of the local electronic structure.