High-quality　tetrapod-shaped　Sn-doped　ZnO　(T-SZO)　nanostructures　have　been　successfully　synthesized　via　the　thermal　evaporation　of　mixed　Zn　and　Sn　powder.　The　effects　of　the　Sn　dopant　on　the　morphology,　microstructure,　optical,　and　field-emission　(FE)　properties　of　T-SZO　were　investigated.　It　was　found　that　the　growth　direction　of　the　legs　of　T-SZO　is　parallel　to　the　[0001]　crystal　c-axis　direction　and　that　the　incorporation　of　Sn　in　the　ZnO　matrix　increases　the　aspect　ratio　of　the　tetrapods,　leads　to　blue　shift　in　the　UV　region,　and　considerably　improves　the　FE　performance.　The　results　also　show　that　tetrapod　cathodes　with　around　a　0.84　atom　%　Sn　dosage　have　the　best　FE　properties,　with　a　turn-on　field　of　1.95　V/μm,　a　current　density　of　950　μA/cm2　at　a　field　of　4.5　V/μm,　and　a　field-enhancement　factor　as　high　as　9556.　©　2013　American　Chemical　Society.