According to the data collected by the National Foodborne Diseases Surveillance Network, the food poisoning caused by Vibrio parahaemolyticus is going up in China recent years. In order to get more information about the V. parahaemolyticus contamination in retail seafoods, 236 samples, including sea crustacean (69), shellfish (116) and fish (51) were collected from the seafood wholesale markets (9), retail markets (128) and hotels (99) in four coastal provinces, Zhejiang, Jiangsu, Guangdong and Fujian in China within the period from September to December 2003. The V. parahaemolyticus in seafood samples was determined qualitatively and quantitatively by the Vitek identification system and the most probable number (MPN) technique. V. parahaemolyticus was isolated from 38 6% of all the samples (91/236). A significantly larger number of positive findings involved the samples collected from Zhejiang Province. Incidence of V. parahaemolyticus in crustacean, shellfish and fish were 49 3%, 37 9% and 25 5%, respectively, with the mean densities of V. parahaemolyticus in positive samples 171 4, 76 9, and 50 7 MPN per 100 grams, respectively. High frequency of V. parahaemolyticus was detected in retail seafoods. It is concluded that this organism needs to be intensively monitored and controlled in raw seafoods.