Molecular weights (M) of organonickel polymers -[Ni(PMePh(2))(2)-1,4-C6F4-Ni(PBu(3))(2)]-1,4-C6F4](n)- and -[Ni(PMePh(2))(2)-4,4’-C12F8](n)- have been obtained from GPC. traces using both a direct calibration (relative to polystyrene standards) and a "universal" calibration (independent of the standards’ nature). The universal method, requiring intrinsic viscosity data, produced M values consistent with light scattering measurements, while the direct method produced ($) over bar M values substantially too low. Using [eta] = K ($) over bar(alpha) and an iterative data-fitting procedure gave alpha = 1.5 for both polymers, and dilute-solution viscosity measurements revealed [eta] to be independent of the solvent nature; both observations indicate that these polymers possess a rodlike structure. The GPC behavior of 13 related organonickel oligomeric species (X-[Ni(PR(3))(2)Ar-F](n)-H, where n = 1-4, X = (ArH)-H-F or Br, Ar-F = 1,4-C6F4 or 4,4’-C12F8, and R = Me, n-Bu, or Ph) was consistent with the polymer performance, in that all oligomers eluted at a given retention time possessed higher MW than did polystyrene eluted at the same time. This is due to the high repeating unit mass which counteracts the expected effect of their rigid-rod shapes. While differences in the fluoroaryl bridging units were found to have no effect on the retention times of the oligomers, separate curves were defined when ancillary PR(3) ligands were uniformly different (i.e., PMePh(2) vs PBu(3)); Oligomers having mixed PR(3) ligands belonged to one of those two GPC curves which is always the one corresponding to the PR(3) at the terminal nickel atoms.