Stimulated rotational Raman scattering (SRRS) of a transversely excited atmosphere‐CO2laser in para‐H2was studied with a liquid‐N2‐cooled multiple‐pass cell. Line‐tunable output from 13.7 to 17.2 &mgr;m was obtained by changing CO2pump lines. Threshold pump energies required for SRRS were measured to be 0.9 and 1.5 J for the 9P(20) and 10P(20) CO2lines, respectively. Above the threshold, the Stokes output energies for the 10‐&mgr;m band pumping increased in proportion to the increase of the pump energies, while the increase of the Stokes output for the 9‐&mgr;m band pumping was limited. Para‐H2pressure dependence of the Stokes output energy showed that the Stokes gain became constant for pressures above 250 Torr at 100 K.