Vitreous cyst, an uncommon finding, was first described by Tansley in 1899. Since then only a few reports dealing with congenital or acquired vitreous cyst have been reported. We report the case of a 16-year-old girl with a unilateral developmental vitreous cyst combined with bilateral retinoschisis. The pathogenesis and histopathology of these phenomena remain unclear, although a few assumptions about the common pathogenesis are discussed. According to our knowledge, this is the first description of vitreous cyst and retinoschisis in the same eye.