Light and X-ray scattering are methods to study nanoparticles and nanostructured materials. These fast and reliable measurements are used for determining sizes and size distributions of various samples as for example nanoparticles, liposomes, micelles, proteins, lipoproteins, etc. Compared to microscopic methods, nanoparticles can be measured by light and x-ray scattering in the suspension or solution. The results obtained are an average of all particles in the scattering volume and thus provide and overall picture of the sample. Beside size determination, X-ray scattering can also provide information about the nanostructure and the shape of nanoparticles in the size range of up to 100 nm.