Ribosome assembly is a complicated process that takes place in both the cell cytosol and nucleus. Shuttling between these compartments of both ribosomal proteins and ribosome subunits is necessary for the formation of active ribosomes. The goal of this work was to make a comparison of ribosomal proteins from nucleus and cytosol of Arabidopsis thaliana. We made separate preparations of ribosomes from cytosol and nucleus. Our proteomic analysis of ribosomes isolated from Arabidopsis thaliana leaves detected 146 ribosomal proteins from cytosol and 135 ribosomal proteins from the cell nucleus. Phosphopeptides from these preparations were enriched using TiO2 and analyzed using nanoLC-MS/MS. This method allowed us to identify 13 phosphopeptides from 11 ribosomal proteins: S2-3, S6-1, S6-2, L13-1, L13-3, L29-1, P0-2, P0-3, P1 (P1-1, P1-2, P1-3), P2 (2-1, 2-2, 2-3), P3 (3-1, 3-2, 3-3) and additionally two phosphopeptides from two ribosomal associated proteins: Nascent polypeptide-associated complex subunit alpha-like protein 1 and 3.