In December 2006 an outbreak of Campylobacter infection occurred in Forth Valley, Scotland, affecting 48 people over a 3-week period. All cases dined at restaurant A. We conducted a cohort study in a party of 30 who ate lunch at restaurant A on 21 December to identify the vehicle of infection. Of 29 respondents, the attack rate in those who ate chicken liver pâté was 86% (6/7) compared to 0% (0/22) for those who did not. Between 1 December and 1.30 p.m. on 21 December the restaurant had used a different method of cooking the pâté. No cases reported dining at the restaurant after this time. The outbreak's duration suggested a continuous source. This is the first continuous source outbreak of Campylobacter documented in Scotland. Chicken liver pâté was the most likely vehicle of infection. This outbreak illustrates the hazards associated with undercooking Campylobacter-contaminated food.