[en] In order to study the possibility of Cr doping of lithium niobate (LiNbO₃) by ion implantation Y-cut congruent lithium niobate samples were implanted with 100 keV Cr⁺ ions at room temperature to fluences of 1x10¹⁶ and 5x10¹⁶ cm^-2. Annealings were performed in a conventional furnace at 600 deg. C, 800 deg. C and 1000 deg. C for 15 min to 240 min under a flowing wet oxygen atmosphere. The optical absorption of the samples was studied in the spectral range from the ultraviolet (300 nm) to the infrared (3.5 μm). Rutherford Backscattering Spectrometry (RBS) and Particle Induced X-ray Emission (PIXE) studies were performed in order to investigate the lattice recovery and the incorporation of the Cr dopant. Annealings at 600 deg. C and 1000 deg. C yielded a virtually complete lattice recovery and the Cr dopant was incorporated substitutionally in the same way as in melt-doped crystals. On the other hand at 800 deg. C the annealing was hampered by the formation of clusters