Abstract The surfactant concentration in miniemulsion polymerization is a very important parameter. At surfactant concentrations lower than a critical value, coalescence of monomer droplets changes their size, whereas concentrations too high lead to the formation of micelles and micellar nucleation in the polymerization step. Inorganic particles dispersed in the monomer phase, with the goal to produce hybrid particles, influence the surfactant concentration needed as shown in this contribution. Values for the ideal surfactant concentration have been determined for different combinations of particles and surfactant. Underlying mechanisms for the required adjustment of surfactant concentration are discussed.