Polymerization of styrene-in-water microemulsions by photoinitiation using the initiator 2,2'-dimethoxy2-phenyl acetophenone (DMPA) produces small nanolatices of the same size as the parent microemulsion (radius = 24-31 Angstrom). This behavior is distinct from previously applied methods where significant particle growth accompanies the polymerization reaction. NMR measurements confirmed that polymerization is complete in under an hour and small-angle neutron scattering established the microemulsion structure before and after polymerization. The approach may be of more general application where retention of structure is sought in microemulsion-based polymer templating procedures.