The reaction between CH radicals and NH3 molecules is known to be rapid down to at least 23 K {at which temperature k = (2.21 +/- 0.17) x 10(-1) cm(3) molecule(-1) s(-1): Bocherel; et al. J. Phys. Chem. 1996, 100, 3063}. However, there have been only limited theoretical investigations of this reaction and its products are not known. This paper reports (i) ab initio quantum chemical calculations on the energy paths that lead to various reaction products, (ii) calculations of the overall rate constant and branching ratios to different products using transition state and master equation methods, and (iii) an experimental determination of the H atom yield from the reaction. The ab initio calculations show that reaction occurs predominantly via the initial formation of a datively bound HC-NH3 complex and reveal low energy pathways to three sets of reaction products: H2CNH + H, HCNH2 + H, and CH3 + NH. The transition state calculations indicate the roles of "outer" and "inner" transition states and yield rate constants between 20 and 320 K that are in moderate agreement with the experimental values. These calculations and those using the master equation approach show that the branching ratio for the most exothermic reaction, to H2CNH + H, is ca. 96% throughout the temperature range covered by the calculations, with those to HCNH2 + H and CH3 + NH being (4 +/- 3)% and <0.3%, respectively. In the experiments, multiple photon dissociation of CHBr3 was used to generate CH radicals and laser-induced fluorescence at 121.56 nm (VUV-LIF) was employed to observe H atoms. By comparing signals from CH + NH3 with those from CH + CH4, where the yield of H atoms is known to be unity, it is possible to estimate that the yield of H atoms from CH + NH3 is equal to 0.89 +/- 0.07 (2 sigma), in satisfactory agreement with the theoretical estimate.