<p>Modification of titanium surfaces using a nanosecond Nd:YAG laser (λ = 532&#xa0;nm) was performed in an aqueous medium. The influence of water compared to air was investigated. Standalone lines of laser impacts with different scanning rates, and laser-treated surfaces with a constant hatch between lines were studied by optical microscopy, SEM–EDS, Raman spectroscopy and XRD. Static contact angles of water and ethylene glycol in laser-treated surfaces were also measured. The standalone laser lines developed a wavy topography with erased contours of the melted zones. A TiO surface layer formed under all the conditions tested, while Ti₂O₃ formed progressively with decreasing scanning rates. EDS analysis of standalone lines showed a higher amount of oxygen compared to treatments in air. Laser-treated surfaces evolved, by decreasing the scanning rate, from goldish TiO-covered to dark surfaces covered with a Ti₂O₃–TiO mixture. TiO₂ was not found in any case in surfaces treated in water, while it is commonly found for treatments in air. Amorphous TiO₂ nanoparticles formed in the laser plume remained in the water medium. The roughness of laser-treated surfaces in water was much lower than in air. Their wettability was controlled by the surface chemical composition. The lowest static contact angles, 5° for water and 0° for ethylene glycol, were found for surfaces containing a Ti₂O₃–TiO mixture. Thermodynamic calculations carried out with the CEA2 program enabled to propose a scenario for the oxidation process in aqueous medium, which explains the dominance of TiO and Ti₂O₃ phases in laser-treated surfaces.</p>