the aim of this study was to investigate the effect of Pit-1 polymorphism on the some blood parameters in dairy local Iraqi cattle, blood samples were collected from (120) healthy dairy cow breeds aged between (4-6 years), in peak stage (40-120) days of lactation, during period of time beginning from September 2017 till January 2018, in the northeast of rural areas in Karbala province. Amplification Refractory Mutation System (ARMS-PCR) techniques was used to detect Pit-1 polymorphism and to classified the genotyping in to three groups; wild group AA, recessive group BB and heterozygosity group AB.The frequencies of genotypes were recorded as 0.06 for AA, 0.70 for AB and 0.24 for BB on the other handthe frequencies of allele were recorded as 0.41 for Pit-1(A) and 0.59 – Pit-1(B).The current study showed no significant decrease (p, >0.05) in the RBC, Hb&MCHC in AB&BB genotype groups compare with AAgenotype group, also the PCV % was no significant difference in all groups. The conclusion our study showed that not found effects of pit 1 polymorphism on the some blood parameter in dairy cow.