Absorption spectra of Dy3+ in DyVO4 yield evidence that this material undergoes a crystallographic phase transition near 14 °K and a magnetic phase transition near 3 °K. The former is believed to be due to a Jahn Teller type of distortion which removes an accidental degeneracy in the Dy3+ ground state. At 4.2 °K and below the effects associated with the magnetic transition have been studied in detail. Zeeman spectra in high fields show the ground state to be anisotropic, with ga = 19, gb ≤ 1, gc ≈ 0.5 (a and b correspond to the original a, a' of the tetragonal cell)