The response of polymers to shock loading is becoming of increasing importance, both as binder systems in plastic‐bonded explosives (PBXs) and as structural materials in their own right. In this paper, we report on the shock Hugoniot of hydroxy‐terminated polybutadiene (HTPB), which is commonly used as a binder system in PBXs, but whose shock response has yet to be presented in the open literature. Results indicate that the shock velocity — particle velocity relationship is linear, similar to some but not all polymer‐based materials. © 2004 American Institute of Physics