An outbreak of Campylobacter enteritis was associated with a restaurant in Louisiana during the summer of 1995. Thirty cases were identified, and four required hospitalization. Campylobacter jejuni was isolated from the patients, and epidemiologic studies revealed illness associated with eating garlic butter served at the restaurant. Three batches of garlic butter prepared by the restaurant associated with the outbreak and a C. jejuni isolate obtained from a patient involved in the outbreak were used for studies to determine the fate of C. jejuni in garlic butter. Studies also were done to determine the efficacy of the heat treatment used by the restaurant to prepare garlic bread to kill C. jejuni. Garlic butter was inoculated with approximately 104 and 106 CFU/g of C. jejuni and held at 5 or 21°C. Results revealed that the survival of C. jejuni differed greatly, depending on the presence or absence of garlic. At 5°C, C. jejuni populations decreased to an undetectable level (<10 CFU/g) within 3 h for two batches and within 24 h for another batch. In contrast, C. jejuni could survive at 5°C for 13 days in butter with no garlic. At 21°C, C. jejuni populations decreased to an undetectable level within 5 h for two batches and to 50 CFU/g in 5 h for another batch. In contrast, C. jejuni was detected at 500 CFU/g at 28 h after inoculation but was undetectable at 3 days in butter with no garlic held at 21°C. The heating procedure (135°C, 4 min) used to make garlic bread by the implicated restaurant was determined not to be sufficient for killing C. jejuni, with the internal temperature of the buttered bread after heating ranging from 19 to 22°C. This study revealed that C. jejuni can survive for many days in refrigerated butter, but large populations (103 to 105 CFU/g) are killed within a few hours in butter that contains garlic. Furthermore, the heat treatment used by the restaurant to melt garlic butter in making garlic bread was not adequate to kill C. jejuni.