[en] The gyromagnetic properties of CrO₂ recording particles have been investigated and compared to those of γ-Fe₂O₃, which have previously been subject to similar studies. Rotational remanent magnetization (RRM) was determined as a function of rotation speed and of the strength of the magnetizing alternating field (AF). Gyromagnetic remanent magnetization (GRM) acquired by anisotropic samples in a static experiment was measured for various peak AF as a function of the angle between the AF and the axis of anisotropy. The asymmetry of GRM curves obtained with non-saturating fields may be related to the incoherent reversal mode of the particles. While GRM (RRM) of the γ-Fe₂O₃ particles had the sign expected theoretically, the gyromagnetic remanences obtained for CrO₂ in both types of experiments were of opposite signs. Possible reasons for the reversed gyromagnetic effect are discussed