The retina is the part of the central nervous system that detects light and transduces it into electrical signals that are relayed to the brain via the axons of the retinal ganglion cells (RGCs). There are numerous functional types of RGCs, each participating in circuits that encode a specific aspect of the visual scene. This functional specificity is derived from distinct RGC morphologies and selective synapse formation with other retinal cell types; yet, how these properties are established during development remains unclear. Here we show that the transcription factor Isl2 is expressed in a distinct class of RGCs that project axons to the image-forming part of the brain. We find that Isl2+ RGCs have distinct morphologies and dendritic stratification patterns within the retina and project to selective visual nuclei in the brain. Molecular analysis shows that most alpha-RGCs, indicated by expression of SMI-32, are also Isl2-GFP RGCs. Taken together, these data suggest that Isl2+ RGCs comprise a distinct class and support a role for Isl2 as an important component of a transcription factor code specifying functional visual circuits.