Pichia pastoris is a eukaryotic microorganism reputed for its ability to mass-produce recombinant proteins, including integral membrane proteins (IMPs), for various applications. This chapter details a series of protocols that progress towards the production of IMPs, their extraction and purification in presence of detergents, and their eventual reconstitution in lipid nanoparticles. These P. pastoris-oriented basic procedures can be further optimized in order to deliver IMP samples compatible with a number of structural and/or functional investigations at the molecular level. Each protocol provides a number of general guidelines, technical hints and specific recommendations, and is illustrated with case studies corresponding to several representative mammalian IMPs.