AbstractBridges, as public structures, are national infrastructure structures. The investment requirements and demands for safe operation should put them at the forefront of engineers' attention. The important SNP bridge in Bratislava (Slovakia), which is one of the first bridges in the world to be suspended entirely on cables, has been the subject of a diagnosis of its health after 50 years of operation. The article describes and documents the individual steps of this diagnostics ‐ identification of the rope material, the status of the rope material and its current strength properties, and the experimentally and computationally determination of the forces in the individual ropes and their cables. The uniqueness of all the diagnostic steps was that they were carried out directly in the outdoor conditions of full operation of the bridge. The achieved results are briefly documented in the paper. Conclusions and further necessary steps for the final comprehensive safety assessment of the bridge operation are formulated.