The epidemiology of 690 Vibrio infections reported in Florida during 1981-1993 is described. Most infections resulted in one of three clinical syndromes: gastroenteritis (51%), wound infections (24%), or primary septicemia (17%). Case-fatality rates were 1% for gastroenteritis, 5% for wound infections, and 44% for primary septicemia. While gastroenteritis had little seasonal variation, 91% of primary septicemias and 86% of wound infections occurred from April through October, mostly due to the seasonality of Vibrio vulnificus and Vibrio parahaemolyticus infections. Infected wounds were largely a result of occupational activities around seawater. Some 68% of gastroenteritis cases and 83% of the primary septicemias were associated with raw oyster consumption. Preexisting liver disease was present in 48% of patients with primary septicemia and was associated with a fatal outcome in both wound infections (relative risk [RR], 28.3; 95% confidence interval [CI], 6.3-127.5; P < .0001) and primary septicemia (RR, 1.9; 95% CI, 1.2-3.1; P < .01).