Objectives. To analyze potential differences in assessment between epidemiological and clinical teams in the management of an emerging infectious disease, and to draw lessons for the management of future crises, the characteristics of patients suspected of having severe acute respiratory syndrome (SARS) who were hospitalized in a Parisian ward were described. Patients and methods. The 90 patients hospitalized between March 16 and April 30, 2003, were included in this prospective study. Data exchanged with local healthcare institutions allowed for both an official case classification ("possible," "probable," "excluded") and a local classification based on an adaptation of the official one, including an additional category in the risk scale, intermediate between "possible" and "excluded" ("doubtful"). Results. The initial assessment differed in 39% of cases (n = 35), based on epidemiological (n = 24) or clinical-biological (n = 11) criteria. The final assessment differed in 54% of cases (n = 47). All patients were officially classified as "excluded" SARS cases, while 47 remained "possible" or "doubtful" cases according to clinicians. Conclusion. A difference in perception existed in approximately 40% of cases, with no impact in terms of epidemic spread or nosocomial exposure, since no probable SARS cases were identified among these patients or their contacts. The comparison of these different but complementary perceptions may yield insights that enhance the interdisciplinary management of future epidemics.