Choroideremia (CHM) is an X-linked retinal dystrophy belonging to the family of blinding disorders. It is characterized by progressive degeneration of the choriocapillaris, retinal pigment epithelium and photoreceptors. CHM is caused by mutations in the Rab Escort Protein 1 (REP-1) gene, which encodes a protein involved in vesicular trafficking. This paper gives an overview of the clinical features, visual function, biochemistry, histology, molecular genetics, pathogenesis, diagnosis and treatment of CHM.