To achieve maximum pore diameter and surface area of porous silica monoliths different structure directing agents (SDAs) (Cationic/anionic/neutral/mixture) were used. BET study showed alteration of SDA’s chain length, composition or concentration have a cumulative effect on controlling the surface area and pore size. PEG in combination with other SDAs like CTAB, SDS, BTMAC, Triton-X100 etc. controlled internal agglomeration along with particles size. The maximum amount of surface area was observed by using maximum chain length of PEG and CTAB.