FAM3C is a secreted factor, which is involved in the epithelial to mesenchymal transition. In transcriptome profiling of the mouse retina using microarray, we found that FAM3C is highly expressed in the retina. FAM3C is expressed in the ganglion cell layer (GCL) of the retina. To explore the function of FAM3C in retinal development, we cloned Xenopus FAM3C (XFAM3C), and performed Xenopus gain- and loss-of-function analysis. Overexpression of XFAM3C resulted in retinal laminar disorganization and an increase in eye size. Loss of function experiments of XFAM3C using antisense morpholino oligonucleotides caused photoreceptor cell dislocation. Cellular differentiation was not affected by either gain- or loss-of-function experiments of XFAM3C. These findings suggest that FAM3C is involved in retinal laminar formation processes in vertebrates.