Nano-delivery systems represent one of the most studied fields, thanks to the associated improvement in the treatment of human diseases. The functionality of nanostructures is a crucial point, which the effectiveness of nanodrugs depends on. A hybrid approach strategy using synthetic nanoparticles (NPs) and erythrocytes offers an optimal blend of natural and synthetic materials. This, in turn, allows medical practitioners to exploit the combined advantages of erythrocytes and NPs. Erythrocyte-based drug delivery systems have been investigated for their biocompatibility, as well as the long circulation time allowed by specific surface receptors that inhibit immune clearance. In this review, we will discuss several methods—whole erythrocytes as drug carriers, red blood cell membrane-camouflaged nanoparticles and nano-erythrosomes (NERs)—while paying attention to their application and specific preparation methods. The ability to target cells makes erythrocytes excellent drug delivery systems. They can carry a wide range of therapeutic molecules while also acting as bioreactors; thus, they have many applications in therapy and in the diagnosis of many diseases.