This volume contains the proceedings of the 13th International Conference on Damage Assessment of Structures DAMAS 2019, 9-10 July 2019, Porto, Portugal. It presents the expertise of scientists and engineers in academia and industry in the field of damage assessment, structural health monitoring and non-destructive evaluation. The proceedings covers all research topics relevant to damage assessment of engineering structures and systems including numerical simulations, signal processing of sensor measurements and theoretical techniques as well as experimental case studies.