The effect of association on chain molecules is studied, and we consider the case of an associating homonuclear disphere fluid as an example. Monte Carlo simulation results of associating hard disphere and Lennard-Jones (LJ) disphere fluids are presented. We consider the molecules to have one association site placed along the molecular axis. For associating LJ dispheres we investigate the effect of bond length on the properties of the molecule. We extend a theory for associating spherical molecules to chain molecules. The agreement between molecular simulation results and predictions from theory is good. We explain the approximations used to simplify the theory and show how a spherical reference can be used to predict the properties of an associating chain fluid.