Traditional-metal-containing　scintillators　are　widely　used　in　X-ray　imaging　due　to　their　efficient　X-ray　absorption　and　output　of　visible　light.　However,　they　suffer　from　heavy-metal　toxicity,　environmental　stability,　harsh　preparation,　and　afterglow.　Metal-free　organic　scintillators　show　a　rising　momentum,　especially　organic-halogen-containing　molecules.　Halogens　are　introduced　to　improve　their　X-ray　absorption,　but　the　resulting　increase　in　spin–orbit　coupling　leads　to　significant　delayed　fluorescence　or　phosphorescence,　affecting　the　response　speed　to　X-rays.　Moreover,　there　is　still　insufficient　practice　in　fabricating　microstructured　organic　scintillators　for　high　spatial　resolution　of　imaging.　Herein,　the　preparation　of　nano　organic　co-crystals　(t-Bpe-IFB　co-crystal,　abbreviated　as　BIC,　t-Bpe　for　trans-1,2-bis(4-pyridyl)ethylene,　and　IFB　for　1,3,5-trifluoro-2,4,6-triiodobenzene)　and　its　application　in　X-ray　imaging　are　explored.　In　contrast　to　previous　single　organic-halogen-containing　molecules,　BIC　generates　nanosecond-scale　fluorescence　through　the　charge-transfer　state　of　the　donor–acceptor.　Its　high　iodine　content　ensures　large　X-ray　absorption,　strong　radioluminescence,　and　a　low　detection　limit　of　85　nGyair　s−1.　The　composite　film　made　of　nano-sized　BICs　and　polydimethylsiloxane　exhibits　a　high　spatial　resolution　of　16.7　lp　mm−1.　Herein,　the　application　of　organic　co-crystals　is　expanded　and　ideas　are　provided　for　the　development　of　new　scintillators.　©　2023　The　Authors.　Small　Structures　published　by　Wiley-VCH　GmbH.