Noroviruses (NVs) are the most common cause of acute nonbacterial gastroenteritis worldwide. An international workshop of 36 people from 5 countries was held on 20-22 March 2002, in Voorhees, New Jersey, to identify barriers to the development of methods for detection of NVs in water and to develop a multiyear research agenda to coordinate efforts to advance the development of methods for detection of NVs. The workshop focused on 3 areas: (1) collection, concentration, and processing of samples; (2) molecular methods for detection and confirmation of NVs; and (3) the detection of infectious NVs through cell culture, infectivity surrogates, and human volunteers. Twelve research projects were developed by the workshop participants.