Interdigital sinus secretions play a role in sexual behavior and reproductive process of sheep. In the present study, it was aimed to characterize the topographical, anatomical and immunohistological features of interdigital sinus in Kivircik sheep. The interdigital sinuses were dissected from 50 forefeet of female Kivircik sheep which were slaughtered in the slaughterhouse. The shape of sinus resembled a pipe and was located between the proximal and distal interphalangeal joints of two digits. The wall of interdigital sinus had three layers as epidermis, dermis and fibrous capsule. Epidermis consisted of a stratified squamous keratinized epithelium. Sebaceous glands, hair follicles, arrector pili muscles, and apocrine sweat glands were in the dermis. Furthermore, there were vessels and adipose tissue in the fibrous capsule. There was immunohistochemical reaction for estrogen receptor expressed in epidermis, apocrin sweat glands and sebaceous glands of interdigital sinus. In conclusion, our results about the topographical, anatomical and immunohistological features of interdigital sinus are very important to understand sexual behavior and reproductive process of sheep, and to make a new approach for its surgery. Furthermore, this study is the first to report the interdigital sinus of Kivircik sheep immunohistochemically.