Flexible multi-layer magnetic recording media comprising a non-magnetic flexible base and, applied thereto, two superposed magnetizable layers which contain a homogeneous mixture of acicular magnetic chromium dioxide in an organic binder.According to the invention, the magnetizable layer adjacent to the base contains a chromium dioxide having a specific surface area, measured by the BET method, of from 15 to 25 m.sup.2 /g, while the outer magnetic layer contains a chromium dioxide having a specific surface area, measured by the BET method, of from 26 to 35 m.sup.2 /g.Such magnetic recording media are distinguished by uniformly high sensitivity over the entire audible frequency range even if close manufacturing tolerances are not maintained.