This study reports on a retrospective evaluation of the current practice of screening for thyroid dysfunction in an adult psychiatric inpatient program. Sixty-four percent of 342 admissions were tested during their hospital stay. Although 13.7% of tests yielded abnormal values on one or more of the thyroid indices, only 0.9% resulted in a diagnosis of hypothyroidism. None of the other abnormal test results led to any specific action being taken. The present pattern of use of thyroid function screening as observed in this study does not appear optimal. Issues in the selection of thyroid screening tests, and the value of the results obtained are discussed.