The goal of our study was to investigate the molecular prevalence of Giardia intestinalis in naturally infected horses in Kayseri, Central Anatolia Region in Turkey, to determine the molecular characterization of the obtained isolates and to exhibit the potential role of horses in zoonotic transmission of G. intestinalis. Fecal samples were randomly collected from totally 150 horses with clinically healthy between March and June of 2018. After the genomic DNA extractions, 25 (16.6%) of the 150 fecal samples, were found positive for G. intestinalis by nested PCR analyses of beta-giardin gene. Phylogenetic analysis of the beta-giardin gene sequences of G. intestinalis showed that the sequences detected in this study belonged to assemblage A that is regarded as zoonotic. Our study is the first report on the presence of G. intestinalis in horses in Turkey. The findings of the present study indicate that future research studies are required to determine molecular epidemiology and geographical distribution of G. intestinalis infections in horses nationwide. In addition, this study also may be helpful to assess the zoonotic potential for public health of G. intestinalis infections. (C) 2019 Elsevier Inc. All rights reserved.