The Master's thesis presents a review of some of the most common non-destructive methods used in inspections of bridging structures. There are different criteria that evaluate non-destructive methods and we identify and justify the relevance of these criteria. Relative importance of criteria is determined by surveying experts that have experience in non-destructive testing. We also rated individual non-destructive (and some destructive) methods with respect to criteria. Our ratings are based on conclusions that were obtained during the review of available literature and survey of experts. Based on relative importance of criteria and ratings of non-destructive methods we sorted them in three classes of importance. We found that non-destructive methods, which rank high on our classification, are also the most commonly used in the field. A SWOT analysis that deals with non-destructive testing, was also done. We found that the usage of non-destructive methods could be increased by technological development and standardization of methods. In the practical part we made a visual inspection of the viaduct Dolgi most in Ljubljana. We recorded visual defects and suggested the most appropriate non-destructive and destructive methods for inspection, in order to obtain more precise information on the current state of built-in material and structure. As the most appropriate methods, we chose the ones that rank high on our ratings, relating to characteristic that we want to acquire. Inspection, involving all suggested methods, was financially assessed, in which we did not consider machinery and equipment needed for conducting the inspection. We planned an inspection on the structure with 2 engineers and 3 technicians and we estimated that they could complete it in two extended working days (20 hours). Elaboration of a basic inspection report would be carried out by one engineer one technician within 5 additional days.