Giardiaarethe most prevalent endoparasites of cats in Austria. To estimate the prevalence and especially the occurrence of different species of these parasites in cats in Austria, 298 faecal samples of cats out of catteries, animal shelters and from private owners were tested for Giardia. They were tested by flotation, a Giardiarapid test and by PCR on the ß-Giardin (bg) locus each. Samples that were tested positive by flotation or rapid test were also amplified at the triosephosphate isomerase (tpi)-locus. In total 22.5% of all samples could be tested positive for Giardiawith at least one method. All methods agreed in 14.9% of positive and in 57% of negative results. There was a high amount of results that were independent to the other methods. PCR matched with flotation and/or rapid test in 26.8% of positive tested samples. Tpi-PCR had slightly better accordance to positive flotation and/or rapid test results than bg-PCR. 14 samples could be successfully sequenced on the bg-locus. After sequencing ten samples were identified as Giardia catiand four as the zoonotic species Giardia duodenalis. Only three of the tpi-amplificates could be sequenced successfully. Tpi-and bg-genotypingresulted in the same species. In one sample which was classified as Giardia catia high amount of ambiguous results and wobbler sequences could be observed. Therefor a mixed infection with Giardia duodenaliswas suspected. At this sample only the bg locus could be amplified. With the presence of Giardia duodenalisin cats in Austria arisk of zoonotic transmission is present. Geriatric, immunosuppressed and very young people are at special risk. In environments with vulnerable persons special caution should thus be taken.