The facility positioning3 problem concerns the location of facilities such as bus-stops, fire stations, schools, so as to optimize one or several objectives. This paper contributes to research on location problems by proposing a reactive multiagent approach. Particularly, we deal with the p-median problem, where the objective is to minimize the weighted distance between the demand points and the facilities. The proposed model relies on a set of agents (the facilities) situated in a common environment which interact and attempt to reach a global optimization goal: the distance minimization. The interactions between agents and their environment, which is based on the artificial potential fields approach, allow us to locally optimize the agent's location. The optimization of the whole system is then obtained from a self-organization of the agents. The efficiency of the proposed approach is confirmed by computational results based on a set of comparisons with the k-means clustering te...