The intracameral injection of hydrogen peroxide induces a sequence of responses in the tissues bounding the anterior chamber. These changes include intraocular pressure, corneal thickness, iris hyperemia, increased leakiness of the iris vasculature, and edema of the ciliary processes as judged from microscopic examination. Some of these responses appear to include inflammatory effects that may be the result of the local release of eicosanoids. Several antagonists of the arachidonic acid cascade, indomethacin, aspirin, dexamethasone, and nordihydroguaiaretic acid (NDGA) were used to examine their influence on the sequelae of hydrogen peroxide injection. Indomethacin, and high dose (7.5 mg/kg) NDGA were most effective in reducing the number of parameters that were altered after intracameral hydrogen peroxide. Microscopic observations supported the physiological changes and the responses to antagonists. The data indicate that a portion of the ocular tissue responses to intracameral hydrogen peroxide in the rabbit eye may be the result of eicosanoid production in these tissues.