Counts of breeding birds in fallow land of Castro Verde region, the main steppe area of Portugal, were carried out during the spring of 1994, and the population densities of the most common species were estimated. The bird community is relatively simple, with a low species richness and diversity. Nevertheless, it includes several species with unfavourable conservation status. The most common species were Calandra Lark Melanocorypha calandra and Little Bustard Tetrax tetrax, with a mean density of, respectively, 5.6 and 2.6 males/10 ha. Other breeding species in the studied fallows include Great Bustard Otis tarda, Corn Bunting Miliaria calandra, Short-toed Lark Calandrella brachydactyla, Little Owl Athene noctua, Stone Curlew Burhinus oedicnemus, Quail Coturnix coturnix and Fan-tailed Warbler Cisticola juncidis. The results suggest that there are differences in population densities in fallows of different age and grazing intensity.