Abstract During emerging epidemics of infectious diseases, it is vital to have up-to-date information on epidemic trends, such as incidence or health care demand, because hospitals and intensive care units have limited excess capacity. However, real-time tracking of epidemics is difficult, because of the inherent delay between onset of symptoms or hospitalizations, and reporting. We propose a robust algorithm to correct for reporting delays, using the observed distribution of reporting delays. We apply the algorithm to pandemic influenza A/H1N1 2009 hospitalizations as reported in the Netherlands. We show that the proposed algorithm is able to provide unbiased predictions of the actual number of hospitalizations in real-time during the ascent and descent of the epidemic. The real-time predictions of admissions are useful to adjust planning in hospitals to avoid exceeding their capacity. ; phone: +31-30-2743559 (Donker, Tjibbe) ; tjibbe.donker@rivm.nl (Donker, Tjibbe) ; National Institute for Public Health and the Environment - PO Box 1 - 3720 BA - Bilthoven - NETHERLANDS (Donker, Tjibbe) ; University Medical Center Groningen - Groningen - NETHERLANDS (Donker, Tjibbe) ; National Institute for Public Health and the Environment - PO Box 1 - 3720 BA - Bilthoven - NETHERLANDS (Boven, Michiel) ; National Institute for Public Health and the Environment - PO Box 1 - 3720 BA - Bilthoven - NETHERLANDS (Ballegooijen, W. Marijn) ; National Institute for Public Health and the Environment - PO Box 1 - 3720 BA - Bilthoven - NETHERLANDS (Klooster, Tessa M.) ; National Institute for Public Health and the Environment - PO Box 1 - 3720 BA - Bilthoven - NETHERLANDS (Wielders, Cornelia C.) ; Pallas Health Research and Consultancy - Rotterdam - NETHERLANDS (Wielders, Cornelia C.) ; National Institute for Public Health and the Environment - PO Box 1 - 3720 BA - Bilthoven - NETHERLANDS (Wallinga, Jacco) ; Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht - Utrecht - NETHERLANDS (Wallinga, Jacco) ...