According to the invention, there is provided a process for producing porous polymer particles, which includes: dissolving in an organic solvent a monomer mixture containing an aromatic vinyl monomer and an aromatic divinyl monomer as major components together with a polymerization initiator to obtain a monomer solution; dispersing the monomer solution in water containing a dispersant and sodium nitrite to obtain a suspension polymerization dispersion; suspension-polymerizing the monomers in the suspension polymerization dispersion to yield porous polymer particles; and separating the porous polymer particles by filtration through a filter medium, in which the sodium nitrite is incorporated into the water in an amount in the range of 0.005 to 0.1 mg per 1 g of the water.