Asymmetric flow field-flow fractionation (AF4) hyphenated with DLS, static light scattering (i.e., multiangle laser light scattering, MALLS) and (differential) refractive index (RI) detection is already a well-established technique for the analysis of the size and shape of a wide range of nanoparticles, including biological, inorganic, and metal nanoparticles. However, AF4-MALLS-RI has only been used for the analysis of crude lignosulfonates and not for the analysis of LNPs so far. An AF4 setup commonly consists of an HPLC pump, an AF4 separation system which regulates the detector flow, cross flow, focus flow and injection flow, and a separation channel equipped with an ultrafiltration membrane. The geometry of the separation channel creates a parabolic flow profile with the highest flow velocity in the center of the channel and lowest flow velocity close to the membrane. The main driving force for the separation of particles according to size is the applied crossflow perpendicular to the detector flow. Small particles exhibit high diffusion coefficients and are thus able to diffuse against the cross flow towards the center of the channel with higher flow velocity and, therefore, elute earlier. In contrast, large particles exhibit small diffusion coefficients and thus stay close to the membrane and therefore, elute later. A combination of different detectors (e.g., MALLS, DLS, and RI) can be used to obtain information regarding the size, distribution and shape of the particles. Static light scattering (MALLS) is typically used to determine the molar mass of polymer molecules in solution but it can also provide information on the radius of gyration (Rg) or root mean square radius (rms)-i.e., particle size based on the particle's mass distribution around its center of mass. Combining MALLS and DLS detection enables to derive the shape factor  from the ratio Rg and Rh-a  of 0.77, 1, 1.36 and 1.55 corresponds to a solid sphere, hollow sphere, prolate ellipsoid and uniform rod, respectively. Here, we assess the potential of AF4 hyphenated with MALLS, DLS and RI detection to obtain information on the particle size, particle size distribution and shape within a single measurement.