The results of two separate studies of the complex between NO and N 2 are reported. The (1 ϩ1) REMPI spectrum of the à ←X transition of the complex between NO and N 2 is presented of improved quality over that reported previously, and the appearance of the spectrum is discussed. The results of high-level ab initio calculations ͓RCCSD͑T͒/aug-cc-pVQZ//QCISD/6-311ϩG͑2d͔͒ on the X 2 ⌸ state are also reported. The indications are that the NO moiety is more freely rotating in the complex than is N 2 , and that a wide angular space is sampled in the zero-point energy level. The appearance of the REMPI spectrum suggests that the à 2 ⌺ ϩ state is ͑close to͒ linear, and RCCSD͑T͒//QCISD calculations on the à state, using Rydberg-function-augmented basis sets, suggest that the lowest energy linear isomer is the ON•N 2 linear orientation. It is clear, however, that the understanding of this complex, and its spectroscopy, is far from complete, and will be challenging.