Purinergic signaling is represented in both peripheral and central nervous system (CNS), and in retina in particular which may be regarded as a part of CNS. Two types of purinergic P2 receptors, which mediate effects of cyclic nucleotides, exist: ionotropic (P2X) and metabotropic (P2Y) ones. While relatively well studied in mammalian retinae, little is known about these receptors in lower vertebrate retinae. That’s why the aim of present study was to investigate the distribution of the ionotropic P2X receptors in frog and turtle retinae which possess mixed and predominantly cone type of retina respectively. All procedures with a frog and a turtle were in accordance with the Bulgarian law for scientific experiments. The animals were deeply anesthetized with halothane and decapitated. The eyes were dissected, and the posterior eyecups with retinae were immediately immersed in 4% (w/v) paraformaldehyde in 0.1 M phosphate buffer for 15-30 min. After fixation, the retinae were dissected from the eyecups and cryoprotected in graded sucrose solutions (10%, 20%, and 30% w/v). Cryostat sections were cut at 14 μm and stored at −20 °C. More than 10 primary antibodies directed to all seven P2X1-7 receptors, in addition to an anti-Vimentin antibody, a marker of Müller glial cells, were applied. The indirect immunocytochemical method was used. The results showed wide-spread expression of all seven purinoreceptors P2X1-7 in both frog and turtle retinae. They were predominantly expressed in Müller cells, the principal glial cells in the retina. All structures typical of Müller cells: the outer and the inner limiting membranes, the cells bodies in the inner nuclear layer, the radial processes in the inner plexiform layer (IPL), and the so called endfeet (frog) or the orthogonal arrays of particles (turtle) in the ganglion cells layer were stained. The colocalizations between P2X1-7 and Vimentin proved that the immunostaining was in the Müller cells. In addition to the glial staining, a neuronal staining was also evident expressed by fine puncta in the inner and outer plexiform layers. Some cell bodies of horizontal and ganglion cells were stained as well. In order to elucidate how the different purinergic subunits combine to form the ion channels, double labeling studies with different couples of P2X antibodies were performed (when it was possible). The results obtained allow us to suggest that the purinergic P2X receptors contribute significantly to neuron-glia signaling in both mixed-type and cone-type retinae of the lower vertebrates.