The strategy for investigating and screening tuberculosis cases appears to be poorly implemented in France. To describe the screening of close contacts (CCs) of patients hospitalized for multidrug-resistant pulmonary tuberculosis (MDR-TB) in three hospitals in Seine-Saint-Denis, 15 patients with a respiratory specimen positive for multidrug-resistant Mycobacterium tuberculosis between January 1, 2000, and December 31, 2005, were included in the study, and their contacts were identified retrospectively. Patient and contact records at Tuberculosis Control Centers (Clat) and hospitals were reviewed after contacting the patients, their contacts, and their treating physicians. Eleven patients were known to the Clat, of whom only 7 had their contacts screened. Multidrug resistance was known to the CLATs for only 7 patients. Among the 4 cases unknown to the CLATs, screening was performed for only one case by the hospital department that treated the patient. Two clusters of three cases were unknown to the Clat. The study highlights current shortcomings in contact tracing, including in cases of MDR-TB, necessitating a reevaluation to improve or even expand the resources and screening strategies in a department heavily affected by tuberculosis. (R.A)