In the absence of risk factors like bicuspid aortic valve, connective tissue disorder, or family history of aortic dissections, degenerative thoracic aortic aneurysm appears to be an indolent disease. Most American and European societies recommend yearly or biannual imaging of the thoracic aorta with computed tomographic (CT) imaging, magnetic resonance (MRI) imaging, and transthoracic echocardiographic (TTE) examination. We aimed to identify the rate of progression and predictors of early degenerative aortic root dilatation (ARD) and ascending aortic dilatation (AAD) over a period of 10 years on the basis of echocardiographic measurements. A retrospective chart analysis was performed on 340 patients (mean age 67.4 ± 11.6 years; 85.6% men; 83.8% White) with known ARD and AAD. Aortic root and ascending aorta measurements were followed by serial echocardiograms from the time of the first diagnosis for a total of 10 years. During this time, the mean change in ARD was 0.28 ± 0.71 mm and AAD was 0.15 ± 0.18 mm. On multivariate regression after adjusting for baseline demographics, risk factors, and medication use, there was no statistically significant increase in their unit change in mean ARD or AAD. In conclusion, mild to moderate degenerative thoracic aortic aneurysm has a minimal change in dimensions over time, and current guidelines recommending yearly surveillance imaging of ARD and AAD need to be revisited to allow a more liberal follow-up interval.