Non-agglomerated amino-functionalized mesoporous silica microspheres are synthesized by a one-pot synthesis from a parent silica material. Narrow pore size distributions in the range from 3 to 5 nm are obtained with alkyltrimethylammonium structure-directing agents (SDAs). By following the pseudomorphic transformation pathway, the particle size distribution and spherical morphology of the parent silica are retained during the synthesis. The products contain accessible and uniformly distributed amino groups. The average pore size and the ratio of small uniform mesopores (<5 nm) to larger mesopores and macropores can be controlled by choosing the appropriate SDA and by adjusting the concentration of the amino-functionalized alkoxysilane precursor, leading to a variety of meso-macroporous hybrid materials.