The fabrication of oxide electronics devices is presently hindered by the lack of standardized and well established patterning procedures, applicable down to the nanoscale. In this work, we propose a procedure to obtain patterns with resolution around 100nm on (La,Sr)MnO 3 /LaAlO 3 /SrTiO 3 heterostructures. Our method is based on a multi-step technique, which includes wet and dry etching, epitaxial masking and e-beam lithography. Our procedure is devised to define independent patterns on the interfacial two dimensional electron gas and on the metallic top electrode, while preserving an allin-situ approach for the heterostructure growth. We show results on nanoscale devices based on (La,Sr)MnO 3 /LaAlO 3 /SrTiO 3 , suitable for oxide spintronics applications.