OBJECTIVE To develop and validate the content of the nursing diagnosis proposal for perioperative thirst. METHODS A content analysis by 34 judges. An online Delphi panel was used in one round, evaluating criteria of relevance, clarity and precision. Wilcoxon's one-tailed test was used and the content validity index to maintain the item was set to 0.80. RESULTS The content validity index in relation to the evaluated items reached levels between 0.87-1.00. The final components of the diagnosis proposal included the following items as defining characteristics: dry mouth, dry throat, dry lips, thick saliva, thick tongue, constant swallowing of saliva, desire to drink water, bad taste in the mouth, and caregiver's report. Related factors are as follows: pre- and postoperative fasting, oral breathing, dehydration, hypovolemia, insensitive loss of hydration by breathing, dry mouth, habit of drinking water, high room temperature. Associated conditions: intubation, use of muscarinic and nicotinic anticholinergics and water restriction. CONCLUSIONS All components of the nursing diagnosis were validated in relation to relevance, clarity, and accuracy, demonstrating high levels of agreement between experts. Qualitative observations were found to be fundamental for both combining and excluding some items. CONCLUSIONS Improvement of refinement and clarity levels of this nursing diagnosis proposal aiding its inclusion in the NANDA International taxonomy and thus enabling greater understanding of the phenomenon of thirst in surgical patients. This study helps to explain and facilitate the identification of defining characteristics, related factors, and associated conditions for nurses, nursing students, and researchers on this subject.