Border checks on poultry and poultry products are being stepped up after Vietnam reported that bird flu had been diagnosed in human patient last week.
Livestock deparment acting director-general Chaiwat Yotakon said on Monday all live birds and meat imported from countries where there is avian flu would be strictly inspected. All poultry farms and raisers of free-roaming ducks along the border would be randomly checked for the virus.
A watch woud also be kept on migratory birds, he said.
Vietnam on Friday reported its first patient with H5 avian flu in eight years. More than 100,000 fowls have been culled in Vietnam this year to try to contain the spread of bird flu.
The patient was a five-year-old girl who had eaten chicken before she fell ill, Mr Chaiwat said. She was in a critical condition.
Thailand has not had a case of avian flu for 14 years.