Vibrio parahaemolyticus culture O from Gulf Coast shrimp was inoculated into whole shrimp and shrimp homogenate to determine its survival at various temperatures and pH values. Although large decreases in viable population occurred during storage for 2 days at 10 to -18 C, survivors were present even after 8 days. No significant differences were observed in the population changes of inoculated whole shrimp as compared with shrimp homogenates. Low populations (5 x 10(2) per ml) of V. parahaemolyticus were destroyed by heating shrimp homogenates at 60, 80, and 100 C for 1 min. With larger populations (2 x 10(5) per ml), some survivors were present after heating at 60 and 80 C for 15 min. None survived 1 min at 100 C. V. parahaemolyticus was very sensitive to pH values below 6.0. Cells survived for several hours in the contents of the porcine gastrointestinal tract.