Here, we investigate if peripheral T-cell activation and proportion of Th17 and T-regulatory cells (Tregs) are associated with aortic aneurysm or aortic diameter in people with HIV. Aorta was examined by computed tomography scans and T-cells by flow cytometry in 428 participants, and aortic aneurysm was found in 32 participants. None of the T-cell subsets were associated with aortic aneurysm, but activated T-cells and Tregs had opposite association to aorta diameter indicating an inverse impact.