High spin states in 90Mo have been populated through the 59Co (35C1,2p2n) 90Mo reaction at a beam energy of116 Me V. Level lifetimes of the positive-parity decay sequence are measured by using the Doppler shift attenuationmethod. It is observed that the M1 transition strengths show a substantial enhancement at high spin. Thisbehaviour may be related to occupation of high Ω orbitals by a pair of g9/2 protons. A deformed, oblate, shapeis suggested above the 13+ state.