A review is made of production defects and in-service damage types that arise in sandwich structures having fiber reinforced plastic (FRP) face sheets. A brief overview is given of relevant defect and damage models and how these models can be used in an assessment of criticality with regard to local and global structure, as a basis for deciding on corrective measures, for the case of a naval ship. Challenges resulting from limitations in inspection techniques are discussed. The concept of damage tolerance is discussed in the light of the above. It is argued that the most suitable and economical approach to achieving damage tolerance is dependent on the application.