Abstract: Anticoccidial effects of Magnoliae officinalis Extract (MOE) were evaluated in chickens following oral infection with Eimeria (E.) tenella. This study was conducted on the 3 days old chickens (n = 30). Those animals were divided with 3 groups; MOE 0.5% treated/infected (n = 10), MOE untreated/infected (n = 10) and non-infected control (n = 10). Chickens were fed a standard diet supplemented with or without MOE for 1 week prior to infection with E. tenella (10,000 sporulated oocysts per chicken). The effects of MOE on E. tenella infection were assessed by two parameters, fecal oocyst shedding and body weight gain. The MOE-fed chickens produced significantly reduced fecal oocysts (p<0.05) when compared to the E. tenella-infected group fed standard diet. Also, MOE-based diet, improved body weight loss caused by E. tenella infection. The data demonstrated that MOE had remarkable anticoccidial activities against E. tenella. This finding might have implications for the development of anticoccidial drug.