Following topical administration to albino rabbits, bunolol hydrochloride, a beta 1- and beta 2-adrenoceptor antagonist, was rapidly absorbed and distributed in ocular tissues, and transformed intraocularly to a single metabolite, dihydrobunolol. The half-life of bunolol was approximately 1.26 hours in the aqueous humor and 1.63 hours in the ciliary body. There was no significant accumulation of bunolol during a four-day period of twice-daily dosing. Most of the drug was excreted in the urine following ocular or intravenous administration.