The matrix elements of the twice-forbidden 473 MeV beta transition between the ground state of 94Nb and the second excited state of 94Mo have been deduced from the experimental values of the shape factor and of the β-γ directional correlation. The results are the following: ∫ R ij = ± (15.5 ± 2.9) × 10 −6, i C A C V ∫ T ij = ± (52.1 ± 6.4) × 10 −6 , C A C V ∫ S ijk = ± (58.2 ± 5.4) × 10 −6, i ∫ A ij = ± (137 ± 6) × 10 −6 . The same quantities have been calculated assuming that the neutrons and the protons outside N = 50 et Z = 40 are in the 1 g 9 2 and 2 d 5 2 orbits , respectively, and that the effective nucleon-nucleon interactions are given by the experimental spectra of 92Mo, 92Zr and 92Nb. The relativistic matrix element has been evaluated using the CVC theory with the approximation proposed by Damgaard and Winther. The radial matrix elements have been computed with harmonic oscillator wave functions. The discrepancies found between the experimental and the theoretical values seem to be due essentially to the simplified shell-model radial wave functions and to the configuration chosen.