The present study investigated the effects of dietary supplementation of purified amino acid (PAA) isolated and purified from animal slaughter house blood on growth performance and immune response of weanling piglets. A total of fifteen, 28 days old, weaned pigs were randomly distributed into three treatment groups, 5 pens per treatment (one head per pen). Each experimental diet was provided to five piglets per group (T0, 0% PAA; T1, 0.1% PAA; T2, 0.5% PAA). The feed consumption was calculated daily and body weight on a weekly basis. The blood samples were analyzed for plasma concentration of biochemical parameters and cytokines using ELISA Kit assay. Pigs fed with the 0.5% PAA have greater average daily weight gain (ADG) and feed efficiency (FE) as compared to those of T0 and T1. However, ADG and FE of T0 and T1 have no remarkable differences. The plasma cytokine levels were lower in T2 as compared to T0 and T1. The blood parameters like total bilirubin, blood urea nitrogen (BUN), glutamate oxalate transaminase (GOT) and glutamate pyruvate transaminase (GPT) were within the normal range in all the treatment groups. The study indicated that supplementation of 0.5% PAA have positive effect on the growth performance of the weanling pigs. Moreover, supplementation of the amino acid isolated and purified from animal slaughter house blood has no adverse effect on palatability of the feed and health of the animals.