Acute loss of central vision may be due to embolic obstruction of the central retinal artery, a cilioretinal artery, or any one of their peripheral arteriolar branches supplying the macular region. Fluorescein angiographic findings in patients with embolic retinal arterial occlusive disease affecting the macula are presented. Fluorescein angiography is helpful in establishing (1) the presence or absence of arterial obstruction, (2) the site of obstruction, (3) the degree of obstruction, and (4) the presence or absence of collateral flow. By providing a means of monitoring flow alterations, the technique may prove to be helpful in regard to prognosis and in evaluation of therapeutic measures for relief of arterial obstruction.