Introduction.-Preoperative information before bladder wall injection of botulinum toxin A (Botox) holds several essential facts to understand and retain by the patients. The aim of this study was a review of essential preoperative information items according to GENULF medical experts. Method.-It was a prospective review from December 2015 to April 2016. Three Delphi rounds had been done from the Survey Monkey software. The initial questionnaire was composed of items from the patient information sheet edited by the GENULF. Each item had been rated by the medical expert on a numeric scale of importance for patient information. The last round asked to experts to confirm items eventually selected. Results.-A list of 27 items regarded as essentials for patient information had been checked by experts after three Delphi rounds, confirmed by 15/19 experts (75%). Best rated items were "learning self -catheterisation is essential" (mean interest 8,5/9; number of rate 8 or 9: 15), "kidney are protected over the long term" (mean interest 8,3/9; number of rate 8 or 9: 15), "efficiency is 6 to 9 months long" (mean interest 8,2/9; number of rate 8 or 9: 14). Discrepancies were mostly on lack of distinction between neurologic and non -neurologic patients. Conclusion.-We identified accurate items considered as essential for preoperative information to patients before bladder wall injection of botulinum toxin A (Botox) by a Delphi method recommended by HAS. (C) 2016 Elsevier Masson SAS. All rights reserved.