The article is devoted to the prospects of hydrocarbon potential of the Paleozoic and Mesozoic complexes of the southern regions of Western Siberia. The problem of identifying and detailed mapping of oil-and-gas prospective objects in the southern regions of the West Siberian basin is associated with a complex nature of distribution of the reservoirs and their spatial relationships with impermeable rocks, which predetermines location of oil and gas deposits at complex non-anticlinal traps. To identify them, it is necessary to apply an integrated method of forecasting, which includes, in addition to the tectonic, lithological and stratigraphic studies of the enclosing rocks, hydrogeological ones as well. The application of hydrogeological criteria for regional, zonal and local assessment of petroleum potential is based on the large role of ground waters in oil-and-gas formation. We have established the hydrogeochemical features of ground waters, identified hydrogeochemical anomalies closely related to hydrocarbon accumulations (I, B, Br, NH₄ etc.). The genetic types of ground waters and degree of their catagenetic maturation are characterized. We have presented the results of paleohydrogeochemical and paleohydrodynamic reconstructions, selected the most probable zones of hydrocarbon generation and accumulation, outlined the main routes of fluid migration. We have studied features of the geological structure and allocated zones of the improved collectors development. A set of somewhat differing criteria of oil-and-gas content for Paleozoic, Middle and Upper Jurassic complexes were justified on the bases of hydrogeological and geological indicators. Based on the suggested complex of criteria, forecast of oil-and-gas content was carried out and sites of various categories of prospects (lands highly-perspective, perspective and without clear prospects demanding further studying) were marked. Application of this approach will promote localization of exploration works and increase efficiency of geophysical methods in search of new deposits of hydrocarbons in the southern regions of the West Siberian basin.