Coccidiosis is caused in chickens by the genus Eimeria spp, and is considered as one of the dominant poultry diseases worldwide. For decades, anticoccidial products have been used for the successful control of this disease. However, long term use of these products has led to the development of resistance. The current study therefore sought to investigate the anticoccidial activity of the methanol leaf extract of Lannea schimperi on experimentally induced Eimeria tenella (E. tenella) infection in broiler chickens in an attempt to provide good alternative therapy due to increasing resistance to the conventional anticoccidial agents. Seven groups (A-G) of 4 birds were used for the experiment and five groups (A-E) were orally inoculated with 1.0 x 103 sporulated oocysts of E. tenella. Groups A, B and C were treated with 25, 50 and 100 mg/kg body weight of L. schimperi methanolic leaf extract respectively and Group D was treated with1.5 mg/ml of amprolium, group E served as negative control. Groups F and G were the uninfected neutral control and were treated with 25 and 100 mg/ml of L. schimperi methanol leaf extract respectively without being infected with E. tenella oocysts. Findings revealed dose dependent anticoccidial effect, with highest concentration of 100 mg/ml giving more activity than 50 and 25 mg/ml of the plant extract. Significant decrease (P ≤ 0.05) in the number of both schizonts and merozoites in the groups (A, B, C, F and G) treated with L. schimperi methanol leaf extract were observed. Large number of schizonts and merozoites were observed in the infected untreated group compared to the treated groups. Significant changes were also seen in the number of circulating eosinophils and lymphocytes. Insignificant changes (P > 0.05) in body weight gain were recorded; however, significant increase (P ≤ 0.05) in the intestinal mucus secretion was recorded in the amprolium treated group. These findings suggest that the methanolic leaf extract of L. schimperi possess anticoccidial activity that may warrant further investigation.