This 60 days experiment was carried out to ascertain the effect of dietary supplementation of Holarrhenapubescens leaf powder (HPLP) on the growth performance, carcass characteristics, intestinal microbial population and some heamato-biochemical parameter of piglets. A total of 50 cross bred male pig with an initial body weight 9.90 ± 0.28 kg were randomly divided into five groups (GA, GB, GC, GD and GE) with five replicates (1 animal per replicate). Feed (Standard) used in this study was Corn-soya based diet compounded with Nutritional Research Council (2012) standard. The first week was a pre-feeding period where piglets were acclimatized and dewormed against parasites and provided unlimited accesses to clean water throughout the experimental period. A completely randomized design method was adopted and piglets in GA was fed standard diet without HPLP while those in GB, GC, GD and GE received same diet supplemented with HPLP at 30 g, 60 g, 90 g and 120 g in that order. Phytochemical screening of HPLP showed that it contained phenols, terpenoids and flavonoids as the most prominent compounds while others include, alkaloids, tannins, saponins and glycosides. Increase in the supplementation significantly improved (P˂0.05) average daily weight gain, average daily feed intake, dressing percentage and reduced feed conversion ratio and mortality among animals. Staphylococcus aureus, Escherichia coli, Proteus spp, Pseudomonas spp and Staphyllococusspp count were significantly suppressed by HPLC, conversely, Lacobacillusspp increased across the group. Pack cell volume, haemoglobin, red blood cell, white blood cell, total protein, glucose, cholesterol, triglycerides, high density lipoprotein, low density lipoprotein were significantly influenced (P˂0.05) except for monocytes, alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase (P˃0.05). Supplementation of HPLP at 120 g/kg diet gave the best result and the performance of animals were not compromised.