Coccidiosis is caused by infection of Eimeria species and an significant parasitic disease in poultry. Various kinds of natural products have been studied to find alternative treatments for coccidiosis in chickens, but the effect of Houttuynia cordata on Eimeria infection has not been investigated. The aim of this study is to study the anticoccidial effect of H. cordata extract (HCE) in chickens after oral infection by Eimeria tenella. Anticoccidial effects of the HCE was evaluated in chickens after oral infection with E. tenella. This study was performed on threeday- old chicks (n = 30). These animals were divided into 3 groups; HCE 0.2% treated/infected (n = 10), HCE untreated/infected (n = 10) and non-infected control (n = 10). The effect of HCE on E. tenella infection was assessed by two parameters; fecal oocysts shedding and body weights gain. the chicks fed HCE significantly reduced fecal oocysts when compared to the E. tenella-infected group fed standard diets (p<0.05). Furthermore, the HCE-based diet improved weight loss due to E. tenella infection. Our data shows that HCE had significant antiprotozoal activity against E. tenella. These findings may have implications for the development of anticoccidial drugs.