Taylor-Aris dispersion analysis (TDA) is an absolute and simple technique which was initially developed for determining the hydrodynamic size of small molecules and macromolecules such as proteins. Nonetheless, in our group we have pushed the design and analysis of Taylor dispersion experiments and we have converted TDA into a routine technique for the characterization of a large portfolio of nanoparticles including organic, inorganic, metallic and non-metallic particles, both in simple and complex biological fluids.