Abstract: The 'zero-range' system follows a collection of random walks on a lattice which interact in the following way: A particle at a vertex decides to jump with infinitessimal rate depending only on the number of particles at its location. Then, it displaces according to a transition probability. We discuss a scaling limit for the position of a tracer particle when the transition probability is mean-zero in one dimension in terms of a diffusion whose coefficients depend on the 'hydrodynamic' particle-mass density.