Hypothalamic syndrome (HS) is a rare and severe complication of craniopharyngioma (CP). Diagnostic criteria have been reported for pediatric patients, but no validated criteria exist for adults, limiting clinical recognition and comparability between studies. The present study applied van Santen et al.'s pediatric criteria for HS to an adult cohort with CP, assessing clinical relevance and estimating HS prevalence in this population. We performed a cross-sectional study of adults with histologically confirmed CP followed in a tertiary center. Clinical, biochemical and neuroimaging data were extracted from medical records. Hypothalamic involvement was classified on Müller grade. HS was assessed on van Santen criteria; weight trajectory, hyperphagia, sleep dysregulation, behavioral symptoms, autonomic dysfunction and daytime somnolence. Effect sizes and proportions were calculated accordingly. Twenty-one patients (57.1% female; median age at diagnosis 24.0 years) were included. Most tumors showed limited hypothalamic involvement, with 76.2% Müller grade 0 and no grade 2. Obesity was common (47.6%), but with no hyperphagia. Only 1 patient (4.8%) met the full diagnostic definition of HS. In this adult cohort, characterized by predominantly non-invasive tumors with minimal hypothalamic involvement, prevalence of HS was low on pediatric-derived diagnostic criteria. These findings suggest that van Santen et al.'s criteria have limited sensitivity in adults and that cohort composition, particularly a low rate of hypothalamic invasion, strongly influences HS detection. Larger and more heterogeneous adult cohorts are needed to validate and refine diagnostic criteria for HS in adulthood.