The textural, structural, morphological, and acidic properties of TiO2/Al-ZSM-12 zeolite synthesized viathe hydrothermal method and using methyltriethylammonium chloride as a template were studied in this study. The structure, size, and shape of the crystallites, and the acidity of the synthesized materials were investigated in detail using the following methods: XRD, low-temperature nitrogen adsorption–desorption, XRF, FTIR, Raman spectroscopy, DRS UV–Vis, DRIFTS, PL, SEM, TEM, solid-state NMR spectroscopy on 27Al, 1H, 29Si, 1H-29Si and 23Na nuclei, NH3-TPD, TG, DSC, DTA, FTIR-Py, FTIR-2,6-dTBP, FTIR-CD3CN, and DRIFTS-acid. The presence of tetrahedral titanium in the TiO2/Al-ZSM-12 zeolite was confirmed by Raman spectroscopy, DRIFT, and 29Si NMR. It was revealed that the crystallites of the TiO2/Al-ZSM-12 zeolite, elongated along the b axis, had a higher acidity compared to the unsubstituted zeolite Al-ZSM-12. The oxidative catalytic activity of the TiO2/Al-ZSM-12 zeolite was studied in the photoinduced decomposition of the crystal violet dye and it was found that the reaction proceeds most efficiently in the presence of H2O2 as an oxidizing agent and TiO2/Al-ZSM-12 as a catalyst (PCA = 0.157%∙min−1).