Biohybrid materials combine the natural diversity of biomolecules with the flexibility of the inorganic sol-gel process. Association of biopolymers with silica is particularly useful for the preparation of three-dimensional hosts for protein immobilization with tailored physical and chemical stability. They are easily tunable in terms of composition, structure and shape, including silicified hydrogels, core-shell particles, and thin films. Such a versatility also allows for the fine tuning of the bio-mineral interface so as to insure the integrity of the encapsulated species, and even improve their biological activity. Biohybrid materials are currently widely explored as drug delivery systems, in biocatalysis as well as to develop new biorecognition devices. They also raise more fundamental questions related to organic-inorganic interactions, both from a chemical and biological perspective.