Abstract: This study examined some haematological and serum biochemical Indices of broiler chickens fed Polyalthia longifolia leaf meal (PLM) as partial replacement of wheat offal. A total number of 250 broiler chickens were used in the experiment which lasted for 8 weeks. They were randomly allotted to five treatment groups with ten (10) birds per treatment and replicated five times in a Completely Randomized Design (CRD). Treatment 1 (T1) contained 0 % PLM, while PLM was used to replace W/O at 5 % (T2), 10% (T3), 15 % (T4) and 20 % (T5) respectively. Feed and water were supplied ad-libitum while standard routine management was observed throughout the period of the experiment. Haematological parameters covered Pack cell volume (PCV), red blood cell (RBC), haemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular heamoglobin concentration (MCHC), white blood cell (WBC) and its differentials while serum biochemistry includes total protein, globulin, albumin, calcium, phosphorus, serum glutamic phospho transaminase (SGPT) and serum glutamic oxaloacetate (SGOT). The results from this study showed no significant difference (P > 0.05) among all the haematological parameters measured. Similarly, PLM did not influence (P > 0.05). Total protein, globulin, albumin, calcium and phosphorus. SGPT and SGOT were significantly different among the treatments (P˂0.05). It was recommended that Polyalthia longifolia leaf meal can be used in growing broiler chickens as feed supplement. This will enhance satisfactory performance, without causing any deleterious effect on the health of the animal.