Objective: To assess the feasibility and effectiveness of an ED-based tuberculosis (TB) screening program. Methods: A TB screening program of adult ED patients was conducted at a university hospital ED with 46,000 annual visits that serves a poor urban community. Patients were screened on weekdays during business hours. ED patients were counseled about the disease and the screening procedure and, after consent, purified protein derivative (PPD) tests were placed. Patients returned in 48-72 hours for reaction reading and post-test counseling. PPD-positive patients received a physical examination, chest x-ray, and HIV testing and were referred to a city TB clinic for possible treatment. Results: Overall, 873 patients were counseled, 630 were eligible for screening, and 374 (59.4%) consented to PPD testing. Of the 203 (54.1%) who returned, 32 (15.8%) were PPD-positive. No active case was detected, but 26 patients were referred to the health department. Eighteen kept their appointments and all 13 who were started on therapy completed treatment. Targeted screening of groups aged 55 years or more, nonwhite groups, and those with other high-risk factors would detect 84% of PPD-positive cases while testing only 48% of eligible patients. Conclusion: An ED-based TB screening program is feasible and can identify many patients requiring treatment. Targeted screening of high-risk groups could reduce the program cost, but would miss some cases.