In the present study, polymorphism of PRL gene at exon-3 and its association with milk production traits inFrieswal cattle was investigated. Prolactin (PRL) gene exerts multiple effects on the mammary gland include mammogenesis, lactogenesis and galactopoiesis. In order to evaluate the PRL gene polymorphism, the restriction fragment length polymorphism (RFLP) method was employed in this research. Blood samples were collected from randomly chosen 54 Frieswal lactating cows. Genomic DNA was extracted from venous blood by the method of John et al (1991) with slight modification and amplified by polymerase chain reaction technique. The PRL gene of the Frieswal cattle was amplified to generate a 156 bp fragment. The PCR products were electrophoresed on 2% agarose gel and stained by ethidium bromide. Then they were digested of amplicons with Rsa I, which revealed two alleles A and B. Data were analyzed by using Pop GenePopgene32 software package and association was analyzed by simple analysis of variance model. In this population, AA, AB, and BB genotypes were identified with 0.315, 0.629 and 0.056 frequencies, respectively. Allele frequencies of A and B were 0.630 and 0.370, respectively. The significant (P<0.05) chi-square value in Frieswal cattle breeds showed that the studied population was not in Hardy-Weinberg equilibrium. It is concluded from the results of present study that the animals of BB genotype for higher lactation length and AB genotype for lactation yield and animals of AA genotype for minimum service period may be selected for future breeding.