Emission of NO from soil was measured in a woodland savanna of Venezuela during the rainy season. Fluxes obtained using closed chamber and gradient techniques were found to agree to within around 30%. The emission varied by up to a factor 4 from one site to another and increased dramatically after rain. An estimate of the total rainy season (7 months) emission range from 0.2 to 1.2 g N m-2. Adding to this our earlier estimate, based on measurements during the dry season, gives an annual emission of 0.3--1.3 g N m-2. These results suggest that NO emission from savanna soils should play an important role in the photochemistry of the tropical region. The NOx concentrations varied diurnally, with up to 20 parts per billion by volume (ppbv) during stable conditions during nighttime. Daytime concentrations, which may be considered representative of a large part of the boundary layer, were found to be around 1 ppbv. ¿ American Geophysical Union 1988