Background/aim: An aneurysm is a pathological enlargement of an artery characterized by the thinning of the elastic fiber layer in the tunica media. Because the aneuritic artery wall is weakened, these vessels can rupture and cause serious bleeding. Surgical methods are often used for the treatment of aneurysms. However, cell-based therapies are less invasive and potentially safer alternatives. In this study, the therapeutic efficacy of rat adipose tissue-derived mesenchymal stem cells (MSCs) was investigated in a new carotid artery aneurysm model.Materials and methods: Arteries were pretreated with elastase to create aneurysms. Gelatin matrices containing MSCs were applied to the outer surface of the elastase-treated carotid artery sections.Results: Healing of the aneuritic arteries for which MSC applications were performed was significantly better than in the aneuritic group. The histological structure of the vessels was largely reconstituted, and the contractile force of the MSC-treated group was similar to the untreated healthy group.Conclusions: Application of MSCs facilitates the healing of aneurysms. Hereby, MSC application could be a promising approach for clinical applications after further validation processes are concluded.