When bioactive glasses are in contact with living tissues, several physico-chemical reactions take place at the material/bone interface, and lead to the formation of a phosphocalcic layer whose composition is close to the mineral phase of bone (hydroxyapatite). This layer is used as a mineralization site for cells and finally allows an intimate bond between the bioactive glass and osseous tissues. This binding is typical of bioactivity, which can be modulated through several parameters of the glass, like composition and textural properties. In this work we present clear evidence of the effect of porosity on the bioactivity of sol-gel derived glasses. Using templating techniques (surfactants and polystren beads respectively), both mesostructured and organized macroporous glasses have been prepared. A nice 3D organization of pores is observed for all glasses by using X-ray diffraction and TEM. Textural properties have been determined using gas sorption and themoporosimetry. Interactions between biological medium and the different glasses have been studied for different delays. At each time period, quantitative chemical maps of samples were recorded by Particle Induced X-ray Emission coupled to Rutherford Backscattering spectroscopy. This technique allows monitoring spatial and chronological evolutions of elemental concentrations, thanks to the excellent sensitivity. The influence of porosity on the bioactivity has been determined and key parameters have been determined.