This investigation evaluates aging characteristics and photocatalytic performance of asphalt cements modified with titanium dioxide (TiO2) at different percentages (3, 5, and 7% by weight of the asphalt binder). Conventional and photocatalytic asphalt cements were used to manufacture specimens of hot mix asphalt (HMA) compacted in the laboratory with a Gyratory Compactor and subjected to environmental conditioning for 6, 12, or 18 months in which they were exposed to temperature changes, rain, and sunlight. FTIR (Fourier-Transform Infrared Spectroscopy), MSCR (Multiple Stress Creep and Recovery), and degradation of methylene blue (MB) tests were carried out to evaluate the influence of aging on the chemical and mechanical properties. Besides, the photocatalytic efficiency of asphalt cements extracted from aged asphalt concrete specimens by the reflux method was also studied. FTIR results indicated that photocatalytic asphalt cements exhibit greater aging resistance over time than conventional asphalt binders. MSCR results showed that mechanical properties represented by deformation recovery and non-recoverable creep compliance parameters improved with TiO2 content and environmental conditioning time. On the other hand, the MB degradation tests indicated that the photocatalytic efficiency of modified asphalt cements increases with the TiO2 content and remains between 20 and 25% for all environmental conditions assessed in this study.