We describe community-acquired rotavirus illness in 1359 children hospitalized at 12 centers in Canada between January 2005 and December 2007. The median age was 1.5 years. Almost half (48.6%) had significant dehydration, almost one-fifth (19%) had clinical sepsis and 7% had seizures at presentation. The median hospital stay was 3.4 days. Severe clinical presentations are less commonly described in surveillance programs.