BACKGROUND Although common and usually benign, hiccups can be an extremely uncomfortable disease. There is not much information about persistent and refractory hiccups. OBJECTIVE To report clinical features of patients admitted in a hospital due to hiccup. METHODS A retrospective study and prospective follow up of patients admitted for hiccup in Hospital Clínico de Santiago de Compostela between January 1998 and May 2005. RESULTS Twenty four patients (age 47 to 91 years, 23 males) were studied. Nineteen (79%) were admitted because of persistent hiccups. In twenty one patients, at inverted exclamation markeast one organic etiology was identified, and thirteen patients presented two or more possible associated conditions. The most common possible causes were digestive tract disorders, followed by central nervous system diseases. Twelve patients had a history of exposure to drugs that potentially could cause hiccups, mainly corticosteroids and benzodiazepines. Chlorpromazine was the first choice treatment in 23 patients, but seven required a second line drug. Average hospital stay was 13 days (range 3-90 days). Twelve patients died during follow up. Death occurred during the first three months of follow up in 61%. CONCLUSIONS Persistent hiccup is often associated with organic conditions, specially advanced tumors of the digestive tract. It is usually associated with a bad prognosis.