Here we report the first X-ray crystal structure of a reactive Rh<sub>2</sub> nitrenoid, enabled by N<sub>2</sub> elimination from an organic azide ligand within a single-crystal matrix. The resulting high-resolution data set demonstrates a long Rh–N bond, consistent with a triplet electronic structure. The demonstration of facile access to reactive metal nitrenoids within a crystalline matrix provides a platform for structural characterization of the elusive transient species at the heart of C–H functionalization.