Use of micrometeorological methods for measurement of surface NO and NO₂ fluxes is problematic due to chemical reactions of the O₃–NO–NO₂ triad in the surface air layer resulting in violation of the assumption of flux constancy with height. Application of a flux-gradient approach close to a short-grass surface (<1 m) minimises this problem, and allows for continuous monitoring of flux and deposition velocity under varying environmental conditions. In this study, we evaluate data collected using a flux-gradient approach for NO and NO₂ flux determination over turfgrass from May to August 2001 in Ontario, Canada. Gas concentrations were determined using two chemiluminescence analysers sampling at 2 Hz from two heights of 0.3 and 0.5 m. Deposition velocities for NO₂ were determined by dividing the calculated flux by the measured atmospheric concentration. The unfertilised grass field studied was a very small source of NO (mean hourly flux 0.45±0.04 ng N m⁻²s⁻¹) and a net sink for NO₂ (–1.76±0.06 ng N m⁻²s⁻¹). Largest NO₂ downward flux occurred during a period with ideal grass growing conditions, and lowest fluxes were measured during the driest period of the summer. This same seasonal pattern was also noted for the NO₂ deposition velocity (mean 2.7±0.17 mm s⁻¹), which was mostly comprised by a surface resistance (daytime mean 436 s m⁻¹). The flux-gradient approach proposed yielded NO₂ flux and deposition velocities within the range of values presented in the literature, and responded to environmental variables in an expected manner.