A total of 463 people died and nearly 4 000 others were injured in road accidents in Thailand between December 27 and January 2, according to officials.
The figure is higher than the one from New Year holidays a year ago, when 423 people were killed in road accidents.
On New Year's Day alone, 89 people were killed, while almost 700 more were injured throughout the country, Thailand's Department of Disaster Prevention and Mitigation (DDPM) said on Thursday.
Known locally as "the seven dangerous days", the seven-day watch period, which concluded on Wednesday this year, is designed to monitor and curb high road fatalities during New Year holidays each year.
According to the DDPM, during the New Year holidays drink-driving was the primary cause of accidents, accounting for more than 30% of them.
Nearly 80% of all the accidents involved motorcycles, the country's most popular vehicle.
Thailand's roads are the ninth-deadliest in the world according to the latest World Health Organisation (WHO)'s report published in December 2018.
The Southeast Asian country was ranked as the second most dangerous country in the previous ranking in 2015.