In 1984-1991, the incidence of salmonellas was studied in wild birds from various sites in the Czech Republic. On an agricultural farm with salmonellosis in calves, salmonellae were isolated from eight birds (seven Passer domesticus, one Serinus serinus) of 31 birds examined. On various agricultural farms with no salmonellosis in farm animals, salmonellae were found in two birds (Columba livia f. domestica) of 2186 birds examined. Of 35 birds caught at a municipal waste-dump site, salmonellae were isolated from one specimen (Larus canus). No salmonellae were found in birds living in reed growths and in various military training areas (557 and 116 birds examined, respectively). In black-headed gulls (Larus ridibundus) from various areas with bodies of water, salmonellae were found in 4.2% of 189 adults and 19.2% of 740 non-flying young examined. S. typhimurium was the most common serotype isolated from gulls. Phage type 141 [corrected] represented 32% of 48 phage-typed strains. This study shows a relationship between the contamination of the environment with salmonellae and their incidence in wild birds.