This paper presents the results of experimental modal analysis conducted on a real bridge deck panel subjected to varying levels of damage. The steel panel was sourced from the dismantled deck of a Bailey-type bridge, which spanned 110 m in total and had a carriageway width of 4.20 m. The study aimed to identify changes in the panel’s dynamic parameters as it deteriorated due to cyclic dynamic loading. Laboratory cyclic loading testing was conducted to simulate real-world traffic conditions, replicating the effects of heavy trucks regularly crossing the bridge. The testing was performed in several stages, with a specified number of cycles applied at each stage. After each stage, the panel was suspended by two hangers on a crane beneath the laboratory ceiling to minimize the influence of boundary conditions on the experimental results. Impact loading was then applied to specific points on the panel’s surface using a hammer, while high-sensitivity accelerometers, arranged in a dense grid of measurement points, recorded the panel’s vibrational response. The modal properties of the panel were determined by analyzing the frequency spectrum of the response to the impact loading obtained from the accelerometer data across this dense network of points. The experimentally derived modal properties were compared with those predicted by a finite element model (FEM) of the panel. This comparison provided validation and deeper insights into the panel’s dynamic behavior as it progressively deteriorated over time.