A new, less sensitive explosive has been prepared and subjected to preliminary characterization tests. The compound, 3-nitro-1,2,4-triazol-5-one (NTO) has a crystal density of 1.93 g/cm3 and calculated detonation velocity and pressure equivalent to those of RDX. Results from initial small-scale sensitivity tests indicate that NTO is less sensitive than RDX and HMX in all respects. A 4.13-cm-diam, unconfined plate-dent test at 92% of crystal density gave the detonation pressure predicted for NTO by the BKW calculation. Finally, NTO can be prepared in high yield from inexpensive starting materials.