Abstract. The gamma-ray multiplicity and total energy emitted by the heavy nucleus 254 No have been measured at 2 di erent beam energies. From these measurements, the initial distributions of spin I and excitation energy E ∗ of 254 No were constructed. The distributions display a saturation in excitation energy, which allows a direct determination of the fission barrier. 254 No is the heaviest shell-stabilized nucleus with a measured fission barrier.