The aim of the study was to test the assumption that mass miniature X-ray screening of the single, homeless (hostel residents) was a cost effective means of controlling pulmonary TB. The study was a prospective experimental screening exercise to identify new cases of active TB, completing treatment. The setting was eight hostels in South London. A mobile X-ray screening facility was set up outside the hostels. Subjects were 547 single, homeless residents in the hostels. They were encouraged to attend for chest X-ray and for active follow- up of abnormal X-rays. No new cases of active TB were found leading to the conclusion that mass, miniature X-ray was ineffective in controlling TB because of its unacceptability and increasing inaccessibility to this population.