Pericarditis is an uncommon extraintestinal manifestation of inflammatory bowel disease (IBD), which may occur at any time during its natural course. Moreover, it may be associated with the medications used to treat IBD, especially mesalamine. We report on two patients with acute pericarditis who were subsequently diagnosed with Crohn's disease. It is likely that mild, longstanding, virtually asymptomatic intestinal disease preceded the onset of pericarditis in both cases.