Data on the thermal stability of a plastic bonded explosive containing an oxidizer cyclotetramethylene tetranitramine (HMX), binder and plasticizer was required in order to satisfy the requirement of NAVORD OD 44811 and to obtain safety information for handling and use. The thermal stability of the PBX was determined by dynamic differential scanning calorimetry (DSC) in sealed/unsealed sample pans and by thermogravimetry (TG) in a nitrogen atmosphere using the variable heating rate method. Critical temperature for self-heating at various sample radii and the 500 day cookoff temperature were calculated. Thermal conductivity, specific heat and thermal diffusivity were determined at the critical temperatures in order to calculate the approximate time to explosion at these temperatures. A DSC self-heating half-life experiment was carried out to confirm that the overall decomposition of the PBX was first order. Published by Elsevier Science B.V.