A family with X-linked megalocornea (XMC) is presented. The most typical ocular features of the disease (cornea globosa, arcus lipoides, mosaic dystrophy of the cornea, pigment dispersion, and cataract) are described and their diagnostic value is discussed by reviewing the literature. Linkage data suggest that the XMC locus maps in the region Xq13-q25, most probably in Xq21-q22.