The association between cryptophthalmos and multiple congenital malformations has been well documented over the last century. Numerous authors have described cases as the cryptophthalmos syndrome, but recently reports of cases without cryptophthalmos have led several authors to use the eponymic designation Fraser syndrome. We have seen seven cases of cryptophthalmos syndrome, including three sib pairs. All presented with cryptophthalmos and bilateral renal agenesis in addition to other characteristic associated malformations. A literature review showed 124 cases in which 27 demonstrated isolated cryptophthalmos, while 97 showed a pattern of multiple congenital malformations. We selected four major and eight minor criteria which enabled us to classify 86 of those cases as having cryptophthalmos syndrome with 11 remaining unclassified. Cryptophthalmos demonstrates equal sex distribution, occurrence in sibs, consanguinity in families with more than one affected child, and lack of vertical transmission--strongly suggesting autosomal recessive inheritance. Isolated cryptophthalmos or cryptophthalmos sequence was sporadic in 16 cases and familial in 11. The familial cases occurred in three families and demonstrated vertical transmission. The pathogenesis of this syndrome is unknown. There are similarities to animal models of maternal vitamin A deprivation and defects in programmed cell death. Cryptophthalmos syndrome should be considered in the differential diagnosis of cases with multiple congenital malformations, especially when they are associated with renal agenesis, even in the absence of cryptophthalmos.