The invention relates to a method of producing a stable substantially aqueous silanized colloidal silica dispersion having a silica content of at least about 20 wt %, comprising mixing at least one silane compound and colloidal silica particles, wherein the weight ratio of silane to silica is from about 0.003 to about 0.2. The invention also relates to a dispersion obtainable by the method, and to a stable substantially aqueous silanized colloidal silica dispersion having a silica content of at least about 20 wt %, wherein the weight ratio of silane to silica is from about 0.003 to about 0.2. The invention further concerns the use of the dispersion for coatings applications and as an additive.