Probiotics are beneficial microorganisms which will be considered as alternatives to antibiotic growth promoters.The aim of the present study was to investigate the effect of probiotic administration in hatchery on performance, blood parameters and immune response of broilers. Three hundereds 1-d-old male chicks (Ross 308) were assigned to five experimental groups of three replications. Birds of control group did not receive any probiotic. Birds of the remaining 4 experimental groups receved probiotics in hatchery via following routes of administration including: in ovo injection, oral, spray and cloacal,respectively. Administration methods of probiotic in hatchery significantly influenced body weight gain in finisher period(p<0.05), feed intakes in finisher and total periods(p<0.05), relative weight of bursa of fabricius in day 28(p<0.05), cell mediated immunity, in terms of mean skin thickness sensitivity to dinitrochlorobenzene (DNCB) in days 28 and 38 (p<0.05), body weight gains in total period and relative weight of spleen in day 42 (p<0.01). Concentration of blood haemoglobin, plasma cholesterol and triglyceride, SRBC antibody, the T-cell mediated response against PHA-M mitogen, relative weight of spleen in day 28 and relative weight of bursa of Fabricius in day 42, were not influenced by various methods of probiotic administration in hatchery (p>0.05). Additionally, these data suggest that oral administration of probiotic in hatchery improved broilers performance.