BACKGROUND: Catatonia is a psychomotor syndrome linked to psychiatric and somatic conditions. Recognized as an independent diagnosis, its rates remain insufficiently characterized. We examined its characteristics in an adult population in Bilbao. METHODS: The study was registered at ClinicalTrials.gov (NCT07315386). Patients ≥18 years with DSM-5-TR catatonia were consecutively recruited across all services at a general hospital in Bilbao between 1/1/2024 and 31/12/2025. Sociodemographic and clinical data were collected at baseline and discharge. Instruments included were Bush-Francis Catatonia Rating Scale, Clinical Global Impression-Severity scale and Charlson Comorbidity Index. Analyses were conducted at episode and patient levels. The study was approved by the local research ethics committee. RESULTS: The study included 49 catatonia episodes (38 patients). Catatonia rates were 6.7 episodes per 100,000 inhabitants/year, 53.3 per 100,000 hospitalizations, and 2.35% among adult psychiatric inpatients. Most patients were female (71.1%). Mean age was 55.9 ± 16.2 years. 85.7% episodes required psychiatric admission. 42.9% had mixed psychiatric and somatic aetiologies (44.9% schizophrenia spectrum disorders; 44.9% mood disorders; 26.5% infections; 16.3% dementia, 14.3% parkinsonism). 32.6% neuroimaging studies showed cerebral atrophy. Benzodiazepines resolved 67.3% episodes; 38.8% required electroconvulsive therapy (ECT). Length of hospital stay (median: 18 days; IQR 9.5-25.5) was only variable associated with catatonia severity (p = 0.02). 30.6% episodes had catatonia-related complications. No deaths occurred. CONCLUSIONS: Catatonia rates in Bilbao were consistent with previous reports. Aetiology reflected complex comorbidity overlap. ECT clustered in older, medically complex episodes. Findings support a relatively stable catatonia clinical expression across underlying conditions.