The structural, electronic, and magnetic properties of anatase TiO 2 samples annealed under different hydrogen pressures are reported. By combining X-ray photoelectron spectroscopy (XPS), Raman, UV−vis, and X-ray absorption near-edge structure (XANES) spectroscopies, evidence of hydrogen incorporation was detected in the anatase structure. Short-time high-pressure hydrogen treatment favors the production of interstitial hydrogen, which, located close to a Ti 4+ ion, transfers charge to it, occupying unoccupied 3d levels. Longtime hydrogenation treatments (10 h) help to rebuild the structure of anatase and heal defects, with hydrogen occupying mainly oxygen vacancies. The presence of reduced Ti (4−δ)+ ions gives the sample its magnetic character at room temperature. Our results show that only a small fraction of the sample is magnetic (probably a superficial region affected by the hydrogenation) but the local magnetization is strong (in the order of hundreds of kA/m). By the choice of pressure and duration of treatment in a hydrogen atmosphere, it is possible to change the magnetic characteristics of the sample.