The temporal and spatial distribution of the nitrite-oxidizing community of a non-fertilized, semi-natural grassland soil was studied to obtain more insight into the possible variation in nitrate production in this soil throughout the year. Data describing the size, potential nitrite-oxidizing activity and serotype composition of the nitrite-oxidizing community are reported. In addition, several abiotic soil parameters potentially related to the activity of this community were measured. Whereas numbers and potential activities largely varied with time and place, the specific affinity for nitrite oxidation, defined as the ratio VmaxKm, was relatively constant. The serotypes Nitrobacter agilis, N. winogradskyi and N. hamburgensis were all present in the top 5-cm soil in every 500-g sample examined, showing that these species co-exist in this soil. By principal component analyses performed with the parameters describing aspects of the community, i.e. most probable numbers, serotype numbers and potential nitrite-oxidizing activities, it was demonstrated that these parameters were all affected in a different way by yet unknown factors. This was confirmed by stepwise regression analyses. If significant, the different biotic parameters correlated with different abiotic factors. Hence, none of the biotic parameters emerged from this study as an indicator that should be used preferentially for the description of the nitrite-oxidizing community in a grassland soil.