Cell necrosis is central to the progression of numerous diseases, and imaging agents that can detect necrotic tissue have great clinical potential. We demonstrate here that a small molecule, termed Hoechst-IR, composed of the DNA binding dye Hoechst and the near-infrared dye IR-786, can image necrotic tissue in vivo via fluorescence imaging. Hoechst-IR detects necrosis by binding extracellular DNA released from necrotic cells and was able to image necrosis generated from a myocardial infarction and lipopolysaccharide/d-galactosamine (LPS-GalN) induced sepsis.