Unconventional petroleum system related with eocene intraplate laccoliths In this paper the elements and processes of a non-conventional petroleum system is described. This system includes participation of a set of laccoliths, forming the "Altiplanicie del Payún" field in the Neuquén Basin platform region. By using 3D seismic interpretation we identify, for the first time, the domical structures generated by laccoliths and the syn-intrusive complex fracture system, which include radial, concentric and polygonal fractures. Intrusive bodies are classified according to their diameter to height ratio, as "low laccoliths" (high diameter / height ratio) and "high laccoliths" (low diameter / height ratio). Their geochemical composition is coherent with types of laccoliths: low laccoliths are trachytic (60% SiO2) and the high laccoliths are rhyolitic (73% SiO2). Trace and rare earth elements contents classify these rocks as alkaline rocks, generated by an intraplate environment. The age of the magmatic event was determined by dating rocks with 40Ar/39Ar as 46-49 Ma that is Eocene age. The emplacement control was transtensional areas related to high order transcurrent faults. Petroleum System includes generation by heat transfer from laccoliths towards black shales on Vaca Muerta and Agrio Formations, immature in Eocene times. Syn-intrusive radial fracturing systems favored primary and secondary migration outward from the intrusive bodies. Hydrothermal convective cells and concentric faults facilitated the return of hydrocarbons to sectors in laccoliths with porosity and permeability to act as reservoirs in the last stages of cooling.