From October 2002 till April 2003, 194 feces samples and 28 liver samples of red deer shot in the Republic of Croatia territory were examined to determine the prevalence of Fascioloides magna in this game population. The majority of study samples were obtained from animals originating from the east part of Croatia, and only a minor proportion from animals originating from the central and west parts and littoral of Croatia. F. magna eggs were detected in 67/194 (34.53%) feces samples and F. magna adults in 8/28 (28.57%) liver samples. The majority of invaded red deer originated from the east part of Croatia, Baranya region, where F. magna eggs were found in 64/120 (53.33%) and F. magna adults in 8/15 (53.33%) animals. F. magna eggs were detected in only 3/74 (4.05%) animals originating from the other parts of Croatia.