The expansion of sodium poly(styrenesulfonate) (NaPSS) polyelectrolyte coils has been studied by light scattering and velocity sedimentation at a NaCl concentration of 0.5-0.001 M. Good agreement between the flexible NaPSS and intrinsically stiff DNA (data from a previous study) is obtained in terms of the conformation-space renormalization-group approach. Present polyelectrolyte the expansion and excluded-volume theories are not adequate to satisfactorily interpret the experimental results.