We examined ten eyes with pseudohypopyon in seven patients with Best's vitelliform macular dystrophy. Fluorescein angiography showed hyperfluorescent defects in the retinal pigment of the superior half of the lesion in all ten eyes. The electro-oculographic findings were abnormal in all four patients who underwent this test. The fluid shifted slightly in two of six patients whose heads were turned to the side for an hour or longer, indicating that the material was probably located between the retinal pigment epithelium and the sensory retina. The volume of the hypopyon increased in one eye.