Angiotensinogen (ANG) is present in the eye. However, the source has not been determined. We showed that ANG mRNA was present in several ocular tissues using RT-PCR with ANG-specifÍc primers. One of 10 iris samples (10%), 1 of 10 ciliary body samples (10%), 3 of 10 choroid samples (30%) and 9 of 10 retina samples (90%) were positive for ANG. Our study provides the first direct evidence that the renin-angiotensin system (RAS) component ANG is synthesized locally in the eye, especially the retina and choroid portion. These are strategic locations for an ocular RAS to influence chorioretinal blood flow, raising the possibility that RAS alterations may be involved in chorioretinal vascular disease.