Alterations in protein phosphorylation, a posttranslational modification (PTM) that regulates many -processes in living cells, is a fundamental mechanism of many diseases, including cancer. Phosphoproteomics, with the combined use of affinity chromatography and electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, is shedding light into phosphorylation signaling pathways at the proteome level and helps to solve difficulties related to sample complexity and phosphopeptide enrichment. One of the most frequent and efficient methods used to enrich samples for the phosphorylated components is titanium dioxide chromatography. Titanium dioxide has a high affinity for phosphopeptides and can also be selective in specific experimental conditions. Here, we describe a protocol for the use of a MALDI plate covered with titanium dioxide nanostructured film, a device developed for a rapid and efficient study of phosphorylated peptides.