Nitric oxide gas (NO) is effectively reduced by retorted oil shale. At 300/sup 0/C half of the NO in a gas stream is removed when the gas stream contacts a bed of crushed retorted oil shale for 0.4 s. The fraction removed in 0.4 s reaches 90% at a temperature of 375/sup 0/C. As long as the reducing agent, presumed to be char in the retorted shale, is not depleted, the rate of reduction of NO appears to be proportional to the partial pressure of NO, and our results can be expressed in terms of a rate constant (k) which is a function of temperature (T, Kelvin) as follows: k = Ae/sup -//sup E/RT/ (s/sup -1/), where A = 4.0 x 10/sup 5/ (s/sup -1/) and E = 59.7 kJ/mole. This rate is many times faster than the rate of reduction of NO by coal char as measured by Furusawa et al. (1983). The principal reduction reaction is unknown; it does not release CO/sub 2/.