Hoang Vu, 32, of Ho Chi Minh City had planned to visit Thailand with his mother later this month, but the political crisis and escalating safety concerns forced him to change his plans.
He said: "I fear for our safety as Thailand has recently experienced bomb attacks and street protests. Traveling there right now isn't advisable. Instead, I'll visit Singapore or Malaysia."
The number of foreign visitors to Thailand dropped by 4.56% year-on-year in the first six months of this year to 16.61 million, according to the Tourism Ministry.
Although Thailand is no stranger to political volatility, the latest changes could not have come at a worse time for the country's economy, Control Risks' Harrison Cheng told Channel News Asia.
In mid-June the World Bank revised its economic growth forecast for Thailand for 2025 to 1.8% from 2.9%.
The number of tourists from China has been declining sharply due to safety concerns following the high-profile kidnapping of Chinese actor Xing Xing in January and a shooting incident at Bangkok's Siam Paragon mall in October 2023.
Naree Suneta, president of the Hostel Thailand Association, said the situation could worsen due to the political instability, particularly demonstrations, Bangkok Post reported.
Border tensions with Cambodia have also added to security concerns for visitors. Last week dozens of tourists were stranded at Thailand's main land crossing with Cambodia after the military halted almost all border traffic.
Thailand began imposing land border restrictions last week, blocking tourists heading into Cambodia, amid mutual retaliation over the border conflict.
The recent discovery of bombs in Phuket and Krabi has heightened safety concerns for travelers in southern Thailand.
Thai police arrested two suspects last week for the placement of explosive devices at several tourist spots in Phuket, including its international airport, The Nation newspaper reported.
The Australian government has issued a travel advisory for its citizens to exercise a "high degree of caution" when visiting Thailand due to ongoing security risks, particularly following the bomb discoveries.
"There's an ongoing risk of terrorism in Thailand," Smart Traveller, the Australian government's travel advisory service, warned.
"Popular tourist areas, including Bangkok and Phuket, could be targeted by terrorist attacks."
Furthermore, Thailand is facing growing competition from regional neighbors such as Malaysia and Vietnam.
In the first quarter of this year Malaysia had led Southeast Asia with 10.1 million tourist arrivals, followed by Thailand with 9.55 million, Vietnam with six million, and Singapore with 4.3 million.
Vietnam also saw the highest number of Chinese tourists in Southeast Asia in the first five months of this year.
Ratchaporn Poolsawadee, vice president of Tourism Council of Thailand, said tourism confidence should be maintained as the industry has already been affected by negative factors since the start of the year including declining confidence among Chinese tourists, the U.S. tariff hike and the Iran-Israel war.
Observers said Thailand must address its political instability before tackling other policy issues to revitalize its tourism industry.