The anticoccidial efficacy of the aqueous neem leaf extract in comparison to amprolium showed that the aqueous extract dose of 800mg/kg compared favourably with 10mg/litre of amprolium in treating the disease, both showed 100% survival rates for infected and treated chickens with zero oocyst per gram at day 4 post treatment. Also, the mean weight (grams) of infected and treated chickens improved significantly (P< 0.05) at day 7-post treatment. Biochemical serum analysis of coccidial infected chickens showed a significant increase (P< 0.05) in alanine aminotransferase (ALT) levels (2.9-245.2) and a significant decrease in alkaline phosphate activity from 4643.9 to 2329.9.