Aim: The effective application of nanoparticles in cancer theranostics is jeopardized by their aggregation in biological media, rapid degradation and clearance. The design of biomimetic nanoconstructs with enhanced colloidal stability and non-immunogenicity is therefore essential. We propose naturally stable cell-derived extracellular vesicles to encapsulate zinc oxide (ZnO) nanocrystals as efficacious nanodrugs, to obtain highly biomimetic and stable Trojan nano-horses (TNHs). Materials & methods: Coupling efficiency, biostability, cellular cytotoxicity and internalization were tested. Results: In vitro studies showed a high internalization of TNHs into cancer cells and efficient cytotoxic activity thanks to ZnO intracellular release. Conclusion: TNHs represent an efficient biomimetic platform for future nanotheranostic applications, with biomimetic extracellular vesicle-lipid envelope, facilitated ZnO cellular uptake and potential therapeutic implications.