‘True’ microcephaly is associated with extremely varied ocular abnormalities, the most frequent being squint and optic atrophy. Within the heterogeneous group of the microcephalies it seems we can isolate a syndrome consisting of microcephaly, mental retardation, chorioretinal dysplasia and sometimes microphthalmia and embryological remnants such as persistence of the primary vitreous or persistence of its minor forms. Genetic transmission of such anomalies is generally considered to be autosomal recessive. The cases we are reporting on suggest that in some cases dominant transmission can be incriminated.