The ocean can be regarded as vast source for new materials and molecules that is still greatly unexplored. The biodiversity that characterizes the marine environment represents an enormous potential for the acquisition of novel microstructures. Marine sponges have morphologies with a wide variety of complex and hierarchical structures from nano to the macro-scale, making it potential candidates for new structured materials. Today, ca. 60% of the synthetic bone graft substitutes available involve ceramic materials, either alone or combined in a composite structure. Ceramic-based biomaterials comprise calcium phosphate ceramics, bioactive glasses and glass ceramics. They are characterized by their bioactivity and unique bone bonding properties, which are usually related to their surface chemistry [1]. The use of biostructures and bioceramics derived from the marine environment for their application as biomaterials is very recent. For instance, several authors have proposed in the last years, the use of different marine species like coral skeletons, sea urchins and sponges as three dimensional biomatrices [2-4].We have focused on the potential of bioceramics obtained from three marine sponges, Petrosia ficidormis, Agelas oroides and Chondrosia reniformis, for biomedical applications. In vitro bioactivity studies promote the precipitation of crystals of calcium phosphate (e.g. hydroxyapatite) on the surface of marine derived bioceramics suggesting these as a new source of bioactive ceramics for tissue engineering and regenerative medicine (TERM) applications.