We describe a new ocular finding, retinochoroidal atrophy (RCA), associated with optic disk paleness in two adult patients with Angelman syndrome (AS) due to maternal 15q11-13 deletion. The ocular involvement described in children with AS consists iris and choroids hypopigmentation due to loss of function of one copy of P gene involved in maternal deletion. The loss of one copy of the same gene of paternal origin leads to a similar ocular phenotype as in Prader–Willi syndrome (PWS). However to our knowledge, RCA has never been described before in PWS, suggesting that other maternally expressed genes, particularly UBE3A, could be responsible for the retinal changes observed in the adult AS phenotype. Although, further investigations would be necessary to better understand the role of the UBE3A in the retina, the findings reported here should prompt a systematic ophthalmologic evaluation adult patients with AS in order to establish the real incidence of RCA and prevent further disability in these patients. © 2003 Wiley-Liss, Inc.