Since the beginning of tight-gas sandstone development in the Río Neuquén field, natural fractures have been suspected to influence production and hydraulic fracture stimulation. In this paper, we analyze available information regarding natural fractures using core, image logs, and outcrop analogs of the Punta Rosada and Lajas Formations to evaluate these possible effects. The Rio Neuquén field is located in the Neuquén basin gulf and at the time of submission of this study, contained 50 wells (16 with image logs and 6 with core) targeting these two tight-gas sandstone reservoirs. The reservoirs consist mostly of low-porosity and permeability, overpressured, feldespathic litharenites and lesser conglomerates overlaying source rocks of Los Molles Fm. The reservoirs are ~3000 ft thick forming an anticline with closure in three directions that terminates against a fault to the NNE. Natural fractures usually show slickensides indicating shear and occur mostly in pelitic intervals, whereas sandstone and conglomeratic intervals are dominated by deformation bands. Deformation bands in core and outcrop analogs are mostly cataclastic, with abundant clay mineral and/or oxide cement, angular clasts, and important grain-size reduction resulting in barriers to fluid flow. Most deformation bands are subvertical, but in some cores several hundred, bed-parallel deformation bands have been observed arranged in meter-sized clusters that correspond with sand-dominated lithofacies. In some wells, the azimuth of natural fractures and deformation bands can be correlated with nearby faults, suggesting a genetic relationship. Because of their potential impact on reservoir permeability, being able to identify natural fractures and, specially, deformation bands in image logs is of utter importance. Although both types of structural discontinuities have been inferred in image logs, detecting and distinguishing between the two is challenging. Deformation bands typically show as conductive planes due to the presence of clay, oxides, pyrite and/or bitumen along them. Moreover, the differential presence of hydrocarbons on both sides of the bands can facilitate their detection. From a productivity standpoint, we conclude that natural fractures in pelites reactivate and cause fluid loss along hydraulic fractures during stimulation, whereas deformation bands are most likely responsible for the reduced fluid flow observed in some wells.