Retinal bipolar cells and ganglion cells are known to possess voltage-gated T-type Ca 2+ channels. Previous electrophysiological recording studies suggested that there is differential expression of different T-type Ca 2+ channel α1 subunits among bipolar cells. The detailed expression patterns of the individual T-type Ca 2+ channel subunits in the retina, however, remain unknown. In this study, we examined the expression of the Ca V 3.2 Ca 2+ channel α1 subunit in the mouse retina using immunohistochemical analysis and patch-clamp recordings together with a Ca V 3.2 knock out (KO) mouse line. The specificity of a Ca V 3.2 Ca 2+ channel antibody was first confirmed in recombinant T-type Ca 2+ channels expressed in human embryonic kidney (HEK) cells and in Ca V 3.2 KO mice. Our immunohistochemical analysis indicates that the Ca V 3.2 antibody labels a subgroup of type-3 cone bipolar cells (CBCs), the PKAβII-immunopositive type-3 CBCs. The labeling was observed throughout the cell including dendrites and axon terminals. Our patch-clamp recording results further demonstrate that Ca V 3.2 Ca 2+ channels contribute to the T-type Ca 2+ current in a subpopulation of type-3 CBCs. The findings of this study provide new insights into understanding the functional roles of T-type Ca 2+ channels in retinal processing.