AbstractObjectiveBodily threat monitoring is a core clinical feature of Fear of cancer recurrence (FCR) and is targeted in psycho‐oncology treatments, yet no comprehensive self‐report measure exists. The aim of this study was the theory‐informed development and initial validation of the Bodily Threat Monitoring Scale (BTMS).MethodsAdult survivors of breast and gynaecological cancers (Study 1: N = 306, age = 37–81 years) and childhood cancer survivors (Study 2: N = 126, age = 10–25 years) completed the BTMS, designed to assess how individuals monitor for and interpret uncertain symptoms as indicating that something is wrong with their body. Participants completed measures to assess construct and criterion validity of the BTMS, and childhood cancer survivors (Study 2) completed the BTMS again 2 weeks later to assess test‐retest reliability.ResultsThe 19‐item BTMS demonstrated excellent internal consistency across adult and childhood cancer samples (α = 0.90–0.96). Factor analyses indicated two subscales capturing 1. Monitoring of bodily sensations and 2. Threatening interpretations of bodily sensations. Two‐week stability estimates were acceptable. For construct validity, the BTMS correlated with body vigilance and anxiety sensitivity. The BTMS also demonstrated criterion validity, yielding significant associations with FCR, intolerance of uncertainty, help‐seeking behaviours, and quality of life. The BTMS was associated with FCR while controlling for body vigilance and anxiety sensitivity, indicating a unique contribution of this theory‐informed measure.ConclusionsThe BTMS shows evidence of sound psychometric properties and could be used to elucidate the role of bodily threat monitoring in the maintenance and management of FCR.