The PRNP gene is connected to scrapie susceptibility in sheep (prion disease). Its polymorphism and expression may influence the occurrence of the disease. In order to study PRNP gene expression level in different ovine tissues, selection of reference genes is needed. Three housekeeping genes (RPL27, RPS29, OAZ1) were chosen for studying PRNP gene expression in ovine brain cortex, midbrain, cerebellum, brain stem, pituitary gland, spleen, liver, skeletal muscle and heart. The primers for gene sequencing were designed based on bovine reference sequences. RPL27 was found to be the most stable reference gene (for brain tissues M=0.322, SDCt=0.486, Stability Value=0.0089; for all tissues M=0.489, SDCt=0.696; Stability Value=0.0093). Regardless of the housekeeping gene, the expression level of PRNP was higher in brain tissues than in other tissues analyzed. A normalization experiment indicated that all candidate reference genes could be used as endogenous controls for studying PRNP mRNA expression in different ovine tissues. However, RPL27 seemed to be the most stable and appropriate for the experiment with many different tissue types and could be used as one of the reference genes for studying gene expression in ovine tissues. Our results confirmed that the PRNP gene is highly expressed in nervous tissue.