Generation of the second Stokes order with a photon efficiency of 68% has been obtained from a single‐pass hydrogen Raman oscillator. The third‐order Stokes generated by four‐wave mixing is effectively suppressed by phase mismatching. The 1.6 times diffraction‐limited pump‐beam quality used in the present experiment was found to be essential to the high‐efficiency second‐Stokes‐order generation.