The sol-gel process offers a wide range of opportunities in terms of tailored nanostructures and nanoporous layers. Here, this is illustrated with various examples of sol-gel-derived multifunctional nanoporous membranes. Hierarchically porous silica membranes and the implementation of different strategies for their functionalization as catalytic membranes are first described. The second part deals with sol-gel-derived photocatalytic membranes and with sol-gel-derived nanoporous membranes enabling reversible chemisorption of hydrogen sulfide.