Fiber-metal laminates (FML) as a combination of metals and fiber reinforced plastic materials are investigated in a variety of current research projects. The intention of combining these two different materials is the compensation of their inherent weaknesses. Certain key parameters for the selection of the constituents of an FML are discussed based on different applications and the related challenges. Therefore, different applications using FML in current research projects at German Aerospace Center are discussed and requirements are deduced. The applications cover UD-CFRP steel laminates, local metal hybridization as well as the use for impact and crash prone structures. The specific challenges in the use of these hybrid laminates like manufacturing and residual stresses are then discussed in more detail as they should also be taken into account when selecting the constituents of an FML for a certain application.