For the first time, the extrusion process is used to produce a perfectly nanostructured organic photoactive layer. Extrusion is an interesting inexpensive and environment-friendly (solventless) option allowing an industrial production scale for the polymer solar cell technology. In this work, this plausible alternative to usual large scale wet-processing techniques (inkjet printing, roll-to-roll coating…) was considered in order to elaborate bulk lamellar ordered heterojunctions employing polythiophene and fullerene C60 based materials, respectively electron donor and acceptor, which were specifically formulated for the preparation of extrudable solar cells. An alternating electron donor/acceptor (D/A) lamellar structure close to the ideal interpenetrating system was targeted and successfully realized. Continuous D and A domains of about 24nm were obtained, i.e. size close to the exciton diffusion length (10-20nm) for π-conjugated organic materials; and a photovoltaic response was evidenced under AM1.5 light simulator conditions. This work open the way to a new promising organic photovoltaic processing method. This work demonstrates the successful use of extrusion as technique for the fabrication of lamellar nanostructured photo-active polymeric films, and suggests a potential application for large scale fabrication of organic photovoltaic solar cells. The originality and novelty of this work first consist in using a one-step continuous extrusion process in order to produce a photo-active nano-multilayer film based on 1024 D(24nm)/A(24nm) alternating layers. After this, the total number of D and A nano-layers was increased to 38000 (19000 D/A interfaces) by consolidation of 37 extruded nano-multilayered films. And a photovoltaic response was evidenced under light, which confirms the achievement of this functional perfect nano-architectured structure by extrusion process.