A post-processing method to predict NO formation in one- and two-dimensional flames is developed. A flame calculation with a reduced number of species and reactions is performed first. The remaining species are computed in a post-processing step. The computational effort is reduced further by introducing steady-state assumptions for intermediates. The results of the post-processing method applied to adiabatic flat flames agree well with complex calculations. Computations of burner-stabilized flames are compared with results of measurements on a ceramic foam surface burner, and the agreement is satisfactory. The post-processor method makes it possible to perform two-dimensional detailed NO computations within a reasonable computing time. As an example, results for a two-dimensional slot burner in a confined environment with cold walls are presented.