The spatial distribution of excreta from intensive cattle grazing was recorded and was described by a negative binomial function. This enabled the proportion of a pasture surface affected by excreta to be calculated for various grazing periods. Where the effect of excreta on the sward was short-lived, as for urine N, or where the total area covered by excreta remained small, as for dung, then little overlapping of effective excreta patches could be expected. Appreciable overlapping of effective patches could, however, occur for the long-lived urine K effect and this should be taken into account when estimating the proportion of a pasture surface affected.