OBJECTIVE To diagnose von Hippel-Lindau disease at an early stage in the presence of atypical retinal lesions. METHODS Case series. METHODS In an 11-year interdisciplinary clinical follow-up study of von Hippel-Lindau disease, 52 patients with retinal angiomas were investigated. RESULTS Besides retinal angiomas, in five patients with von Hippel-Lindau disease or in the close relatives of such patients, unusual retinal vascular hamartomas other than retinal angiomas were detected. Retinal hamartomas are characterized by small, moss fiber-like, relatively flat vascular lesions with smooth and occasionally irregular margins and without enlarged afferent and efferent vessels. They are located within the superficial retina, usually adjacent to a retinal vein. In addition to typical peripheral retinal angiomas, a 28-year-old man with a pheochromocytoma had a treelike hamartoma. In another family, a brother and sister both had circumscribed red hamartomas with irregular outlines close to the retinal vessels. On fluorescein angiography, the early arterial filling of the hamartomas in two of these patients was striking. CONCLUSIONS It is prudent to be aware of these unusual vascular retinal changes in von Hippel-Lindau disease. They may occur in isolation without additional retinal angiomas (as in four of our patients) but may suggest the presence of von Hippel-Lindau disease.