Emulsion detonation synthesis (EDS) is a newly developed process to synthesize nano-sized ceramic powders based on the detonation of 2 water-in-oil emulsions. The process provides high pressure and temperature along with rapid quenching. In this work, we report the formation of wurtzite phase BN (w-BN) for the first time by EDS process, using hexagonal BN (h-BN) as the precursor. Characterization studies demonstrated the formation of w-BN with sizes varying from nanometer to micrometer scale either embedded in or grown from h-BN matrix. These findings provide a new avenue to synthesize metastable and superhard BN phases.