Blood samples (collected and dried on filter paper) from 2 338 animals which had died in the zoological gardens in Berlin and other cities in the German Democratic Republic were examined by indirect haemagglutination test. Toxoplasma antibodies were found in 430 (18.3%) animals. Out of this number 1 113 were mammals and among them 201 (18.1%) were found to be positive. Out of 1 225 birds 228 (18.6%) were positive. A total of 194 species or subspecies (89 mammal species and 105 bird species) reacted positively. On the basis of these findings the spread of toxoplasma infection under zoo conditions as an artificial ecosystem in urban environment is discussed.