The Vaca Muerta Formation is the main source rock in Neuquén Basin, and the primary unconventional reservoir in Argentina. Thin facies of bituminous marls and mudstones with carbonatic intercalations and Total Organic Content between 1% and 10% constitute the deposits of Vaca Muerta Fm., interpreted as the product of distal and central basin environments. Several seismic techniques such as AVO and simultaneous inversion are used for reservoir characterization. However, these methods have limitations in areas where vertical variability of reservoir properties are below the seismic resolution. To overcome this limitation and describe clinoform sedimentary sequences, a 3D stochastic seismic inversion was performed in a region of approximately 100 km2. A volume of acoustic impedance was obtained after a model-based deterministic inversion. This outcome was used to constrain the vertical and lateral trends of acoustic impedance as a prior model for stochastic seismic inversion. The inverted geostatistical models were further used to improve the prediction of a spatial and vertical distribution of reservoir properties by integrating well-log data and seismic volumes. The P impedance volumes obtained from deterministic and stochastic inversion are used to obtain porosity and TOC volumes for petrophysical characterization of the reservoir. An increase in the detail of the models was obtained from the stochastic inversion. In addition, stochastic inversion provided a better understanding of the uncertainty of the available data and therefore a basis on which to analyze the obtained results