The universality of the gel equation, a recently suggested rheological equation for polymers at the gel point, was tested on three well-defined cross-linking polyurethanes (PU). Stoichiometric amounts of triisocyanate cross-linker (DRF) were mixed with a,w-dihydroxypoly(propy1ene oxides) (PPO) of nominal molecular weights 425, 1000, and 2000. As the cross-linking reaction progressed at 30 C the evolution of the viscoelastic properties was measured. At the gel point, the storage modulus G'and the loss modulus G were found to be congruent and proportional to d2, where w is the frequency of the oscillatory shear experiment. The same behavior was previously observed with an end-linking poly(dimethylsiloxane), however, with tetrafunctional cross-linking points.*** This suggests universal validity of the rheological equation for stoi- chiometrically balanced end-linking polymers. (3) where + is the rate of deformation of the sample at GP. The only material parameter in the equation is the gel strength S. The apparent simplicity and clarity of the gel equation suggests its universal validity for end-linking polymers with balanced stoichiometry. We therefore selected three po- lyurethanes (PU) and studied their rheology in the vicinity of GP. Similarly to the PDMS system which was used in the earlier experiments, these PU networks are also formed by an end-linking reaction of stoichiometrically balanced chemical species. However, the cross-linking process occurs by a different reaction and the cross-link functionality was chosen to be 3 instead of 4 for the PDMS. Nevertheless they are found to exhibit the same rheological behavior at GP as PDMS. This will be shown in the following.