Sections of retinas from albino and pigmented rats were studied histochemically by the naphthol and lead methods for lysosomal enzymes (acid phosphatase, aryl sulfatase, glucosaminidase and β-glucuronidase). Activity of the enzymes studied (except β-glucuronidase) is demonstrable in granules which by their staining properties are identified as lysosomes. The matrix of the lysosome stains positively in PAS preparations and is diastaae resistant. The organelles are distributed mainly in the pigment epithelium, outer limiting membrane, inner nuclear layer, ganglion layer and inner limiting membrane of the retina. © 1969 Springer-Verlag.