Pterygium is a common conjunctival disease which is mainly attributed to chronic ultraviolet light exposure. Previous studies have focused primarily on the clinical characteristics, surgical management and the pathogenesis of pterygium, but the differences between primary pterygium and recurrent pterygium have been less frequently documented. This article reviews the differences in clinical manifestations, histopathological findings, and laboratory parameters between primary pterygium and recurrent pterygium and summarises the latest findings regarding these differences.