The effect of retrobulbar lidocaine administration on ocular and optic nerve blood flow was studied in phakic rabbit eyes using a radioactive microsphere (85Sr) technique. Blood flow measurements were performed 15 minutes after retrobulbar injection of 40 mg of lidocaine in ethanol to the right eye of each rabbit. Blood flow measurements were determined for the iris, scraped ciliary processes, choroid, retina, and optic nerve. There was no statistically significant (P<0.05) difference in lidocaine treated eyes compared to contralateral control eyes. An identical volume of retrobulbar ethanol alone had no effect on regional blood flow.