In August 1983 the old stone bridge at Arta (Epirus-Greece) was in risk of serious damage due to underscouring, which was the result of irregular flows of the river Arachthos, over which the bridge is built. To protect the bridge, remedial measures were decided immediately and first stage protection works were executed. Permanent protection works for the river channel and bridge pillars followed and completed the first stage works. Parallelly with the execution of the protection works, a limited investigation programme was carried out. As part of this programme, Historical-Archaelogical data were collected, site and soil investigation works were carried out and structural analyses were performed to provide the basis for the assessment of the structural damages (which occured prior to scouring) and lead to proposals for repair of the bridge. The results of the first stage of this study proved the need for an extended investigation programme in the area of the west abutment, the findings of which provided additional data for the foundation of the bridge. This report aims to present the main features of the structural analyses and their correlation with actual damages of the bridge, as well as with the results of the in-situ investigations.