The aim of the study was to evaluate the effects of the methnolic leaf extract of Vernonia amygdalina and its major fractions on the endogenous life cycle stages of Eimeria tenella in exprimentally-infected broiler chickens. Experimental birds were divided into seven groups of two replicates and dosed with 105sporulated oocysts of E.tenella and treated with extracts. Two birds from each replicate were sacrificed on days 5 and 6 postinfection for histopathological examination of caecal sections. In addition, the secondary oocysts recovered from treated birds at 7 days postinfection were evaluated for viability by their ability to sporulate after incubation in 2.5% potassium dichromate. Histopathological investigation of sections of the ceaca for schizonts and gametocytes revealed reduced number of schizonts and gametocytes in the caeca of birds of the treated groups compared to those of the positive control. Of interest is the efficacy of the mehanolic extract and the butanol fraction, greatly diminishing the number of schizonts and gametocyte to remarkable levels. Most of the secondary oocyts recovered from chickens treated with methanol extract, hexane fraction, butanol fraction, and aqueous residue fraction had only 33.78, 1.94, 0.36 and 0.96% non-viable oocysts, respectively, compared with those recovered from birds in the positive control group, with observed sporulation rate of 95.46%.