Sol-gel-derived SiO2-CaO-P2O5 porous glass monoliths with a dual hierarchical pore structure including both macropores of similar to 20-200 micrometers and mesopores similar to 5-20 nanometers in size are prepared in the presence of the drying control chemical additive formamide, for a possible application as scaffolds in bone tissue regeneration. While the mesopores are intrinsic to the sol-gel processing, the interconnected macropores are achieved through a polymer-induced phase separation together with the sol-gel transition, by adding a water-soluble polymer, poly(ethylene oxide), to the precursor sol. The textural nanopore structure is controlled through solvent exchange procedures and the addition of urea. The overall pore size distribution obtained by mercury intrusion porosimetry was found to shift to larger pore sizes when formamide is added. In vitro tests are used to evaluate the bioactivity. The cell-support function of the resultant scaffolds is also assessed in vitro using osteoblast-like cells cultured for 2 days. The results show that the scaffold has a significant bioactivity and a good ability to support the attachment of MC3T3 preosteoblast cells.