This study reports the first direct kinetic measurements on the NS radical. NS was produced by photolysis of N4S4 at 248 nm and was detected via laser-induced fluorescence. A fast reaction was observed. between NS and NO2, with k = (2.54 +/- 0.12) x 10(-11) cm(3) molecules(-1) s(-1) (error = 2sigma including systematic errors) at 295 K. The rate coefficient shows a small negative temperature dependence over the range 295-673 K, which is represented by k = (2.57 +/- 0.11) x 10(-11)(T/295 K)(-1.10+/-0.10) cm(3) molecule(-1) s(-1). The reaction was also investigated using density functional theory (B3LYP/6-31G**) to calculate the geometries of the stationary points on the potential energy surface, coupled with Brueckner doubles and perturbative triples to determine energy differences. The calculations show a direct route from reactants to N-2 + SO2, via a series of isomers of NSNO2, with no energy barrier higher than that of the entrance channel. It is also possible that the reaction forms SNO + NO; this channel has a higher barrier than that found on the N-2 + SO2 route, which is also below the entrance channel, but involves fewer isomerizations. No reaction was observed between NS and O-2 or NO, at temperatures up to 623 K and upper limits of 1 x 10(-15) and 3 x 10(-14) cm(3) molecule(-1) s(-1), respectively, were placed on these rate coefficients.