Abstract The Delaware and Val Verde basins are in the southeastern part of the Permian basin of West Texas and southeastern New Mexico. They have a combined surface area of about 21,000 sq mi and contain about 54,000 cu mi of possibly gas-bearing sedimentary rocks. At the beginning of 1965 there were 63 dry- or nonassociated-gas fields producing in the Texas part of the basins and 35 in the New Mexico part. Prospects for finding additional gas reserves of substantial size in this area appear to be good. Exploration for oil in this area began in the early part of the century, but only in the last 10 years have market conditions justified the search for gas alone. In much of the basin area Ellenburger dolomite of Early Ordovician and Cambrian age rests on the Precambrian basement, although on the southeast clastic beds of Cambrian age intervene. The Ellenburger rocks contain some of the largest gas reserves in the region. Middle and Upper Ordovician strata are present in most of the basin area. Devonian and Silurian carbonate rocks are important gas-yielding reservoirs. Above the Woodford Shale, which lies on the Devonian carbonate beds, are the Mississippian and Pennsylvanian Systems. All series of the Pennsylvanian produce gas somewhere in the basins; the Morrow, Canyon, and Cisco are the most important. In the lower part of the overlying Permian System, coarse clastic rocks of Wolfcamp age form important gas reservoirs. One important field and several smaller ones yield gas from the upper part of the Delaware Mountain Group in the Upper Permian Guadalupe Series. Upper Triassic continental strata lie on the evaporites of the Ochoa Series of the uppermost Permian. On the Triassic rocks lies the Cretaceous System, comprising both the Comanche and Gulf Series in the southeast but only the Comanche Series in the north. Cenozoic and Recent sand and gravel form much of the surface of the north and west parts of the Delaware basin, and piles of Tertiary volcanic material form the mountains in the southwestern part of the region. Brief resumes are given of Brown-Bassett, Clara Couch, Coyanosa, Gomez, Ozona, Puckett, Sonora, Toyah, Atoka Penn, Bell Lake, and Indian Basin fields. A study of these fields indicates that there are two major classes of deep-gas prospects in the basin area. One consists of the very deep structural traps in the depths of the basins which form prolific reservoirs but are expensive to explore. The other class comprises the stratigraphic sandstone traps along the northwest and east sides of the Delaware basin. These offer opportunities for development of moderate reserves at medium cost. All exploration in the basin area is dependent on the maintenance of favorable marketing conditions.