Considering the various uses of different types of asphalt mixtures in the world, the evaluation of the different behaviors of this mixture is significant in terms of performance and safety. Despite extensive research on the self-healing properties of asphalt mixtures, the specific impact of carbon nanotube (CNT)-modified Gilsonite asphalt binder on self-healing performance has not been thoroughly investigated. This study fills this gap by exploring the synergistic effects of CNT and Gilsonite on the self-healing behavior of asphalt mixtures, providing new insights into enhancing pavement properties. The goal of this study was to examine the self-healing behavior of asphalt mixtures containing asphalt binders modified with CNT. For this purpose, 7 wt% of Gilsonite-modified asphalt binder, as well as 0.05, 0.1, 0.2, and 0.3 wt% of CNT-modified asphalt binder, were added to the virgin binder with penetration grade 60/70 and mixed by a high-shear mixer. Then, the four-point bending test was conducted on the modified asphalt binder samples and examined under the constant strain test conditions at 500 and 800 microstrain levels. The results indicated that the addition of CNT to Gilsonite-modified asphalt binder had a remarkable impact on increasing the self-healing characteristics of asphalt samples. Moreover, results showed that the healed samples recovered the stiffness from a minimum of 69% to a maximum of 99% compared to the base samples. Also, the self-healing rate was considerably different between the base asphalt sample and mixtures modified with Gilsonite and CNT under constant strains. The findings suggest that incorporating CNT into Gilsonite-modified asphalt binder significantly enhances self-healing properties, with potential applications in extending the lifespan of pavements and reducing maintenance costs, and as a result, the economic efficiency and sustainability of transportation infrastructure increase.