Purpose: Pterygium is a pathologic process with angiogenic and tumor cell like characteristics. Chemokine and chemokine receptors may contribute to the formation and growth of pterygia. The aim of this study was to assess the expression of stromal cell derived factor (SDF)-1, as an angiogenic chemokine, and its receptors, CXCR4 and CXCR7, gene transcripts in pterygia., Methods: RNA was extracted from tissue samples of 33 patients with primary pterygium and 35 volunteers with conjunctiva as the control group. Then the mRNA expression of SDF-1, CXCR4, and CXCR7 was assessed through quantitative Real Time PCR method using appropriate primers., Results: SDF-1 and both receptors transcripts had significantly higher expression in pterygia samples compared to the control group ( P < 0.05). The ratio of CXCR7 transcript expression to CXCR4 was 26.4 in patients while it was 11 in controls., Conclusion: As SDF-1 and its receptors, CXCR4 and CXCR7, were up-regulated in pterygia, SDF-1/CXCR4/CXCR7 axis may contribute to pterygium formation which can be possibly restrained by down-regulating this signaling pathway.