Characterization of the distribution of insulin receptor (InsR) mRNA in tissues is crucial to understand insulin physiology in dairy cattle. The expression of the InsR gene in various tissues of three male neonatal Holstein calves was analysed using reverse transcription polymerase chain reaction. The results showed that the InsR mRNA was detectable in the liver, subcutaneous adipose, Semitendinosus muscle, pancreas, kidney cortex, spleen, heart, lung, mesenteric lymph node, aorta, duodenum, colon, hypothalamus, pituitary, cerebral cortex and cerebellar cortex. Expression of InsR mRNA was particularly higher (P<0.05) in the liver, Semitendinosus muscle, pancreas, aorta, hypothalamus and pituitary tissue than other tissues detected. The broad tissue expression of the InsR gene indicates that the InsR has important physiological functions in multiple tissues in neonatal Holstein calves.