Is it safe to cross the border by land?

Yes, provided you stick to established, reputable bus companies like Giant Ibis or Mekong Express. Avoid accepting 'help' from strangers at the border who claim to be officials.

Can I do this trip in one go?

Technically yes, but it is exhausting. It is highly recommended to stop for at least a night in Siem Reap or Phnom Penh to break up the 20+ hours of total transit time.

Crossing Southeast Asia: Traveling Overland from Thailand to Vietnam

Traveling overland requires moving through Cambodia via the Poipet border crossing. You will take a bus from Bangkok to Siem Reap, navigate through Cambodia, and then take a bus or boat from Phnom Penh to Ho Chi Minh City.

Book your Bangkok to Siem Reap bus. Avoid 'all-in-one' cheap bus tickets sold by street kiosks in Bangkok, as they often involve scams at the border. Instead, book a direct bus via Giant Ibis or Transport Co. Ltd from Mo Chit Bus Terminal.
Navigate the border crossing. At the Poipet-Aranyaprathet border, get your exit stamp from Thailand, walk to the Cambodian side, and complete your visa-on-arrival or show your e-visa. Keep $30 USD in cash ready for the visa fee if not using an e-visa.
Transit through Cambodia. Spend 2–3 days in Siem Reap to see the temples, then take a 6-hour bus to Phnom Penh. Use reputable companies like Giant Ibis or Mekong Express for safety.
Cross into Vietnam. Take the international bus from Phnom Penh to Ho Chi Minh City. This is a 6–7 hour journey. The bus staff usually collects passports to handle the immigration process at the Moc Bai border for you.

Is it safe to cross the border by land?: Yes, provided you stick to established, reputable bus companies like Giant Ibis or Mekong Express. Avoid accepting 'help' from strangers at the border who claim to be officials.
Can I do this trip in one go?: Technically yes, but it is exhausting. It is highly recommended to stop for at least a night in Siem Reap or Phnom Penh to break up the 20+ hours of total transit time.