High-pressure homogenization as an emulsification technique and the production of solid lipid nanoparticles are strongly interlinked. The impact of an emulsifier as an important influencing parameter for both processes is described exemplarily for Polysorbate20 and sodium caseinate. Regarding the emulsification process, Polysorbate20 led to a higher improvement of the droplet breakup than the protein sodium caseinate. These results were compared with different published investigations on the crystallization behavior of fats with the same emulsifiers. Considering the crystallization behavior of the lipid phase, sodium caseinate was more advantageous in stabilization of the crystallized particles. The most important factors which have to be taken into account were determined and analyzed.