Aim: The aim of this survey was to assess US dentists' practice for sterilising or disinfecting new endodontic files and gutta-percha. Materials and methods: A random sample of general dentists and endodontists from all 50 US states were contacted either by email (Survey Monkey) or by post, and asked to complete a questionnaire on sterilisation and disinfection practices for new endodontic files and gutta-percha. Results: A total of 105 questionnaires were returned, with a response rate of 4.2% and 25% for email and post, respectively. Sixty-one percent of endodontists and 56% of general dentists answered 'yes' or 'sometimes' to the query regarding sterilisation of new endodontic files prior to use. The difference in the responses of specialists and general dentists was not statistically significant, despite the fact that general dentists were statistically more likely to answer that they were 'very' or 'somewhat' concerned about the effects of sterilisation on the structural integrity of endodontic files. Half of the general dentists responded 'yes' or 'sometimes' to disinfection of new gutta-percha cones, with endodontists (59%) statistically more likely to do so than general dentists (32%). Equal percentages (84% each) of endodontists and general dentists responded that they place endodontic files and gutta-percha on a sterile work surface in the dental operatory. Conclusions: The results indicate that a majority of the respondents use endodontic files and/or gutta-percha straight out of the manufacturers' packaging. There is a need to reinforce education about existing recommendations and rationale for sterilisation/disinfection of endodontic instruments and materials before use as part of the infection control process. Schlagwörter: disinfection, endodontic files, gutta-percha, sterilisation, survey