This Special Issue represents a set of contributions presented in the CINPAR 2016 international conference which took place in Porto, Portugal, during 26-29 October 2016. Structural engineering experts in strengthening and repair of structures need to have a comprehensive knowledge over a set of issues: structural integrity, fatigue and fracture of materials and structures; surveying and diagnosis techniques for material characterization; structural defects; repairing and reinforcement of materials and structures; physical and mechanical properties of the materials. The advances in structural expertise, over the last years, have revealed a substantial appeal from the players and their roles in the construction industry and the appearance of new materials and construction techniques. Recent construction market forecasts show a considerable growth in the investment on the strengthening and repair activities. This special issue of the CINPAR2016 conference is composed of a total of 8 papers covering some topics related with the evaluation of current damage condition, repairing and reinforcement of materials and structures.