**Welcome** This repository contains open data, open code, and all questionnaire versions of the Catastrophising Questionnaire. Note that the final version of this paper has been published at Royal Society Open Science, https://doi.org/10.1098/rsos.201362. **Questionnaire versions** The final version in the main questionnaire versions folder is in Gorilla layout, such that instructions and all response anchors can be seen. This does, however, mean the questionnaire is several pages long. The short version is also in this format. The questionnaire can be scored by converting each 'never' response to a score of 0, 'rarely' to 1, 'sometimes' to 2, 'often' to 3, and 'always' to 4 - these item scores should then be summed, leading to a score between 0 and 96. Higher scores represent individuals who are more likely to catastrophise, lower scores represent individuals who are less likely to catastrophise. *Development* In the 'Development' folder there are the versions of the questionnaire used in earlier experiments, and different formats of the final Catastrophising Questionnaire. Note that the versions used in experiments 1 and 2 were preliminary, and are thus superseded by the version marked 'final' in the folder above. The other formats of the final Catastrophising Questionnaire are: a PDF without Gorilla formatting that could be used for pen and paper testing (named non-Gorilla); and a single-page PDF with only the items listed (named items-only). **Open code** This code is written in R, and is in the format of an R notebook. The libraries required to run this code are listed at the top of the notebook. You will need to define your own workingdir (chunk 2) where you have saved the data from *Open data*. Running these notebooks will save the main figures into your 'workingdir', so be cautious if this is not something you want - if you choose not to do this, please type '0' into the popup that asks about it. **Open data** This data can be used to replicate all the analyses in the Catastrophising Questionaire paper. If you require additional variables to run other analyses, please contact us - we have chosen to be minimalist with the data we upload to ensure confidentiality of participants. **Github** This code is also available on github: https://github.com/apike02/catastrophising_questionnaire