Rate coefficients for the reaction (NCN)-N-3 + NO -> products (R3) were measured in the temperature range 251-487 K at pressures from 10 mbar up to 50 bar with helium as the bath gas. The experiments were carried out in slow-flow reactors by using pulsed excimer laser photolysis of NCN3 at 193 or 248 nm for the production of NCN. Pseudo-first-order conditions ([NCN](0) << NO) were applied, and NCN was detected time-resolved by resonant laser-induced fluorescence excited near 329 nm. The measurements at the highest pressures yielded values of k(3) similar to 8 X 10(-12) cm(3) s(-1) virtually independent of temperature and pressure, which indicates a substantially smaller high-pressure limiting value of k(3) than predicted in earlier works. Our experiments at pressures below 1 bar confirm the negative temperature and positive pressure dependence of the rate coefficient k(3) found in previous investigations. The falloff behavior of k(3) was rationalized by a master equation analysis based on a barrierless association step (NCN)-N-3 + NO <-> NCNNO((2)A '') followed by a fast internal conversion NCNNO((2)A '') <-> NCNNO((2)A'). From 251-487 K and above 30 mbar, the rate coefficient k(3) is well represented by a Troe parametrization for a recombination/dissociation reaction, k(3)(T,P) = k(4)(infinity)k(4)(0)[M]F(k(4)(0)[M] + k(4)(infinity))(-1), where k(4) represents the rate coefficient for the recombination reaction (NCN)-N-3 + NO. The following parameters were determined (30% estimated error of the absolute value of k(3)): k(4)(0)[M=He] = 1.91 X 10(-30)(T/300 K)(-33) cm(6) s(-1)[He], k(4)(infinity) = 1.12 X 10(-11) exp(-23 KIT) cm(3) s(-1), and F-C = 0.28 exp(173 K/T).