AbstractObjectiveClinical fear of cancer recurrence (FCR) was recently defined by a group of experts during a Delphi study. Five criteria were agreed upon, namely: (a) high levels of preoccupation, (b) high levels of worry, (c) that are persistent, (d) hypervigilance and hypersensitivity to physical sensations that e) may result in functional impairment. No existing instruments comprehensively capture all these criteria for clinical FCR.MethodsTo remedy this gap, a set of three patient‐reported outcome instruments including a one‐item screener, self‐report questionnaire, and semi‐structured clinical interview, named the Ottawa Clinical Fear of Recurrence instruments, were developed. To do so, the research team first conducted a literature review of potential items. Additional FCR experts discussed the content of the screener and interview. The self‐report's items were assessed for content validity by the same expert panel using Likert ratings and the Content Validity Index to narrow down the number of items. The three instruments were piloted with a group of cancer survivors to assess face validity following the European Organization for Research and Treatment of Cancer recommendations.ResultsThe literature review and content validity assessment led to a final draft pre‐pilot of 23 potential items for the self‐report questionnaire. The instruments were piloted. Pilot study participants suggested changing wording and response options (particularly for the self‐report) for greater clarity.ConclusionsBased on the feedback received, minor modifications were made, mostly for the self‐report. In general, content and face validity for the three instruments were good for both experts and cancer survivors.