Correlated ab initio calculations are used to analyze the interaction between nitrosyl hydride (HNO) and CH3X (X = F, Cl, Br). Three minima are located on the potential energy surface of each complex. The more strongly bound contains a NH center dot center dot center dot X bond, along with CH center dot center dot center dot O; CH center dot center dot center dot O and CH center dot center dot center dot N bonds occur in the less stable minimum. Binding energies of the global minimum lie in the range of 11-13 kJ/mol, and there is little sensitivity to the identity of the halogen atom. Unlike most other such hydrogen bonds, the NH covalent bond in this set of complexes becomes shorter, and its stretching frequency shifts to the blue, upon forming the NH center dot center dot center dot X hydrogen bond. The amount of this blue shift varies in the order F > Cl > Br.