A ten-case report of Streptococcus suis infection was reported in Lamphun, northern Thailand from 1999 to 2000. Ten patients were admitted to Lampoon Provincial Hospital with a history of high fever, watery diarrhea, severe myalgia and ecchymosis rashes. The disease progressed rapidly and all patients died within 24-48 hours after admission from complications such as disseminated intravascular coagulation (DIC), acute renal failure (ARF) or acute respiratory distress syndrome (ARDS). Epidemiological data revealed that all cases were healthy men aged between 40-49, residing in the same geographical area and had a history of raw pork or uncooked pig's blood consumption prior to their illnesses. Blood culture and genetic investigation (16 s rRNA polymerase chain reaction with restriction enzyme PstI) confirmed diagnoses of the same species of Streptococcus suis infections.