In the tree shrew retina individual rod and cone photoreceptors can be readily identified and quantified because their perikarya are arranged in a single layer. This retina is therefore an ideal system for testing the specificity of photoreceptor-directed antibodies. Here we describe the staining properties of polyclonal antibodies against (rhod)opsin and retinal S-antigen in the tree shrew retina. The (rhod)opsin antibody exclusively and completely labelled the rod population. The antibody against S-antigen also labelled all rods and, in addition, a regularly arrayed subpopulation of cones, which we argue to be the blue-sensitive cones. In the context of our findings, the labelling of pinealocytes with these antibodies is discussed.