A 48 day nutritional experiment was conducted to determine the haematological and serum biochemistry characteristics of broilers fed Annona muricata leaf extract. A total of 96 day old Abor acre broiler birds were randomly divided into four experimental groups of 24 birds per treatment and replicated three times with 8 birds per replicate in a completely randomized design (CRD). T₁ was the control and fed water without the test ingredient while T₂, T₃ and T₄ were given Annona muricata leaf extract at different concentrations (20,40 and 60mls) per litre of water respectively. At the end of the trial, blood samples were collected from the birds via marginal wing vein and examined for biochemical parameters such as total protein, creatinine, and some important enzymes of nutritional interest such as; alkaline phosphatase (ALP),aspartate amino transferase (AST), and alanine amino transferase (ALT). Haematological parameters were also analyzed for white blood cell, Haemoglobin, red blood cell, mean corpuscular volume, mean corpuscular haemoglobin concentration, packed cell volume and mean corpuscular haemoglobin. Significant differences (P < 0.05) were observed in packed cell volume and mean corpuscular haemoglobin, while the other haematological parameter were similar (P>0.05) across the treatment groups. The serum biochemical parameters differed (P < 0.05) significantly across the treatment groups. Treatment three (40mls inclusion of Annona muricata leaf extract) performed better than other treatments. This indicated that, Annona muricata leaf extract at 40mls per one litre of drinking water for broiler birds had the best performance and therefore was recommended for broiler production