We report a case of recurrent accumulation of pleural effusion, successfully treated with goreisan. A 61-year-old man had been receiving treatment in our hospital for congestive heart failure, aortic regurgitation, and alcoholic hepatitis. On **********, acute aggravation of congestive heart failure caused retention of this pleural effusion. Although the effusion initially disappeared, following puncture of thoracic cavity, this pleural effusion increased again and he was admitted to our hospital. We administered goreisan without a change in other oral medications, and the pleural effusion disappeared and did not recur thereafter. goreisan is generally prescribed for dry mouth and urinary problems associated with various disorders of the body's fluid metabolism. In this case, it is thought that goreisan showed an action which affected water regulation.