The general acceptability of plants with proven records of medicinal values in the tropics in recent times has necessitated the use of dried avocado pear in the broiler diet and its possible effects on haematological variables and biochemical indices. The study focused on haematological and biochemical responses of broilers to varying levels of the inclusion of dried avocado pear seeds. The inclusion levels were 0% of the dried avocado pear seed meal as a control, 2.5%, 3.5%, 4.5% and 5.5%. The experiment lasted for eight weeks: four weeks for the starter phase (for the acclimatization of the birds and the maturation of their GIT) and four weeks for the test trials (the finisher phase). The result showed significant differences (P<0.05) in the haematological parameters, which implied that the inclusion of the dried avocado pear seeds in broilers’ diets had a positive influence on platelets, lymphocytes, monocytes, eosinophils and heterophils. The presence of lymphocytes indicated the adequate production of antibodies, which could prevent opportunistic infections, as was observed during the experimental trials with birds without the test ingredients. The dried avocado pear seed had a positive influence on aspartate aminotransferase (AST), albumin (ALB), total protein (TP), triglyceride and high-density lipoprotein (HDL). It could be concluded from this study that avocado pear seed has significant effects on improving the haematological and serum characteristics of broiler birds, with the highest values recorded in T4 (4.5%) and T5 (5.5%), respectively.