In aeronautic industries adhesive bonding is a common technique to repair composites. In this study interrupted in-situ observations by X-ray computed tomography (XCT) were used to investigate the crack initiation and propagation in scarf repaired CFRP-laminates. Specimens were tested in two conditions: i) as-received ii) after conditioning under hot/wet conditions to determine the moisture influence on the damage behaviour. The specimens were tested in-situ in a high resolution XCT device with a voxel size of (8 μm)3 at different load levels. The defects of each load step were segmented and compared to each other. An influence of the absorbed moisture neither on the damage propagation behaviour nor on the tensile strength could be observed. In particular, a concentration of cracks in the area of repair-ply terminations of the scarf joint could be determined.