Abstract: Stone mastic asphalt (SMA) has been used for decades to extend the life of asphalt pavements, especially in terms of ruttingresistance. However, its performance and cost-effectiveness have been debated. This study evaluates the long-term performance of an SMApavement and its control hot-mix asphalt (HMA) pavement in eastern Washington State. The field performance of the SMA pavement andHMA control pavement was evaluated based on the data in a pavement management system and site visits. Field cores were extracted fromboth the SMA and HMA pavements and subjected to indirect tension (IDT) dynamic modulus tests, creep compliance tests, studded tire wearresistance tests, and intermediate and low temperature IDT fracture tests in the laboratory. SMA and HMA asphalt binders also were extracted,recovered, and subjected to performance grading, multiple stress and creep recovery tests, and monotonic tests. This study found thatin the field, the SMA pavement outperformed the HMA pavement in terms of rutting and cracking resistance. Results of the laboratory tests ofthe field cores verified that the SMA material performed better than the control HMA material in terms of top-down, bottom-up, and thermalcracking resistance. Results of the recovered binder tests showed that the SMA mixture exhibited less aging than the HMA control mixtureand that the recovered SMA binder provided better rutting, fatigue, and thermal cracking resistance than the HMA binder. Therefore, SMApavements, when designed and constructed properly, are a viable solution for prolonging the life of asphalt pavement. DOI: 10.1061/(ASCE)CF.1943-5509.0000939. © 2016 American Society of Civil Engineers.Author keywords: Stone mastic asphalt (SMA); Hot mix asphalt (HMA); Long-term performance; Material property.