Background: PERIOSTIN (POSTN) is an extracellular matrix (ECM) protein that plays an important role in the metastatic process and cancer cell migration. As implantation is a similar mechanism to metastasis, it has been hypothesized that POSTN may also play a role in the implantation process. Aims: The aim of the present study was to compare POSTN and progesterone levels during the early pregnancy stage in Damascus goats. Methods: Forty goats were synchronized using progesterone based sponges and were mated upon estrus signs display. While ten goats were kept as control (CON) and were not allowed to mate. Blood samples were taken through jugular venepuncture from CON and synchronized goats on day 13, 15, 17, 19, and 21 of breeding. Progesterone and POSTN levels were determined by enzyme-linked immunosorbent assay (ELISA). Later the pregnancy diagnosis was confirmed by transabdominal ultrasonography on day 50 after mating. Results: Progesterone level was influenced by status of pregnancy and day of observation with an interaction between the status of pregnancy and day of observation in goats. Whereas POSTN level was only affected by the day of observation. Conclusion: POSTN level did not vary with progesterone level during phase of embryonic implantation in goats; however, standardization and application of different procedures for POSTN assay in a large group of animals might be useful as an early pregnancy biomarker in goats.