<p>Deterministic Lateral Displacement (DLD) microsystems offer the ability to fractionate microparticles based on their size with high resolution. So far, this type of separation system has been used mainly for analytical purposes. However, when it comes to industrial applications for the fractionation of real particle suspensions, higher throughputs are of increasing interest. Since real particle suspensions are not only spherical, this work deals with the fractionation of non-spherical particles at higher volume flow rates. Resolved three-dimensional (3D) CFD-DEM simulations were used to investigate the separation behavior of spheroids at different particle aspect ratios, sizes and Reynolds numbers. The spheroidal particles were approximated using the multi-sphere approach. The results generally show that the separation size decreases with increasing Reynolds number. The behavior of the particles generally differs for prolate and oblate as well as for more compact and less compact spheroids depending on the Reynolds number: Prolate spheroids show a tendency to align themselves longitudinally in the gap in the direction of flow and tumble around the post, whereby this behavior becomes stronger with increasing aspect ratio and Reynolds number. Compact spheroids follow the streamlines better and turn their axis of symmetry parallel to the post. This is why their separation size corresponds roughly to their smallest axis and particles with a larger aspect ratio are in contrast more prone to deflection. While oblate spheroids tumble around the posts at low Reynolds numbers, inertial conditions result in a behavior that can be described by inclined log-rolling. Therefore, it is no longer the smallest but rather the largest axis that is crucial for fractionation. The separation of spheroidal particles is, therefore, not exclusively influenced by the size of the smallest axis of the particles, but by a combination of several shape-specific and inertia-dependent effects.</p>