The objective of this study was to investigate the effect of autochthonous Lactobacillus plantarum feeding on growth performance, carcass traits, serum composition and faecal microflora of broiler chickens. The results showed a significant positive effect (p< 0.05) of probiotic on body weight and feed conversion ratio. Coliform counts in the fecal matter of broiler chickens receiving probiotic were lower than the analogous population in control birds (p<0.05). In contrary, lactic acid bacteria (LAB) number increased (p<0.05) in fecal matter of experimental group. At the end of the study, the degree of serum cholesterol reduction resulted in a 20.31% compared to the control group (p<0.05). The experimental group had significantly lower serum triglycerides (p<0.05). It was concluded that autochthonous probiotic improved growth and feed efficiency in broilers chickens and considering the improvements in carcass traits. This probiotic possess the property of reducing cholesterol and triglycerides in the blood and possess a positive effect on the gut microflora.