Background Thirst is one of the most intense and distressing symptoms experienced by patients in the intensive care unit (ICU), and no validated measurement tools exist. Validating a thirst measurement tool for the ICU population could be a first step in gaining a better understanding of thirst in ICU patients and aid the development and implementation of strategies regarding the prevention and control of thirst. Aim The objective of this study was to determine the validity and reliability of the "Thirst distress scale for patients with heart failure (TDS-HF)" in measuring thirst distress in adult ICU patients. Methods Content validity was established by an expert panel consisting of ICU nurses, intensivists and five ICU patients. Concurrent validity, known-groups validity and internal consistency were determined in a consecutive sample of 56 awake and oriented ICU patients with a median age of 70 years (IQR: 57-74). Results Content validity of the TDS-HF in the ICU population was low, with item-content validity indexes between 0.25 and 0.75. Concurrent validity was high as Spearmans correlation between TDS-HF and the numeric rating score (0-10) for thirst distress was 0.71. Internal consistency was high (Cronbachs alpha 0.78). When comparing groups, only higher blood urea nitrogen was significantly related to higher scores on the TDS-HF (P = .003). Conclusion The TDS-HF has high concurrent validity and reliability in measuring thirst distress in ICU patients. Nevertheless, questions remain regarding the applicability and content validity of the scale, which should be further explored before the TDS-HF can be used in the ICU. Relevance for clinical practice The TDS-HF can be used to explore thirst distress and to evaluate interventions. Individual items of the scale can be used to explore the nature of thirst distress in individual patients.