The long-term fate of biomedically relevant nanoparticles (NPs) at the single cell level after uptake is not fully understood yet. We report that lysosomal exocytosis of NPs was not a mechanism to reduce the particle load. Biopersistent NPs such as silica and gold remained in cells for a prolonged time. The only reduction of the intracellular NP number was observed via cell division, e.g. mitosis. Additionally, the NPs distribution after cell division was observed to be asymmetrical, likely due to the inhomogeneous location and distribution of the NP-loaded vesicles in the mother cells. These findings are important for biomedical and hazard studies as the NP-load per cell can vary significantly. Furthermore, we highlight the possibility of biopersistent NP accumulation over time within the mononuclear phagocyte system (MPS).