For imaging with different modalities, labels, which provide contrast for all modalities, are required. Colloidal nanoparticles composed out of an inorganic core and a polymer shell offer progress in this direction. Both, the core and the polymer shell, can be synthesized to be fluorescent, magnetic, or radioactive. When different cores are combined with different polymer shells, different types of particles for dual imaging can be obtained, as for example, fluorescent cores with radioactive polymer shells. Properties and perspectives of such nanoparticles for multimodal imaging are discussed.