Vietnam and Cambodia are pretty close and the two countries share 3 international border crossings.
There are many tourists in Cambodia from Vietnam and vice versa. And among all the cities of Cambodia, Phnom Penh and Siem Reap are the two cites that people from Vietnam tend to visit most.
Phnom Penh is the capital and the largest city in Cambodia. It is also a famous destination to the tourists for many traveling attractions. While Siem Reap is another famous tourist city of Cambodia with also a lot of well-known travel sites.
Although the distant between the two countries is close, the transportation is somehow complicated and time-consuming. There are different ways either overland or by plane to travel between Vietnam and Cambodia, not only by plane like the most of other countries. Unfortunately, there is no train to travel between Ho Chi Minh and Cambodia.
And obviously, you need a tourist visa to travel between the two countries. Somehow you can get it at the airport when travelling by plane but you’d better to prepare it in advance.
Following are the detailed information about the transportation between Ho Chi Minh City (Vietnam) and Phnom Penh (Cambodia).

From Ho Chi Minh to Phnom Penh by Bus

Bus run is definitely a straightforward, cheap and comfortable way to get from Phnom Penh to Ho Chi Minh. It is most recommended among tourists.
It takes about 5 – 7 hours to take a bus from Ho Chi Minh directly to Phnom Penh. The ticket price is about $15.
Most buses from Ho Chi Minh to Phnom Penh are air-conditioned with toilets onboard. Bottled water and moist tissues are free for all passengers, in some buses, even food is distributed at no cost. Additionally, there are stops along the journey for toilet, food, facilities using and also a stop at the border.
Ho Chi Minh has a bus terminal at the western end of Pham Ngu Lao street while Phnom Penh has no central bus terminal so each bus has a different parking lot.
Bus tickets are available online so you can easily book the ticket yourselves through some simply steps like choosing the bus line, ticket prices then trip schedules, using your smart phones, laptop or tablet. The number of the seat will be written in your ticket. Or you ask your guesthouse, hotel for help and more information if you don’t know how to get the ticket.
There verified bus companies providing tour from Ho Chi Minh to Phnom Penh: Sapaco, Kumho Samco, Mekon Express, Giant Ibis, the Sinh Tourist, Thero Express, Khai Nam transport, Phuong Trinh Tourism, and Virak Buntham. Most of them have station at Pham Ngu Lao Street which is about 8 to 10 kilometers from the Tan Son Nhat International Airport of Ho Chi Minh City to the south.
Some notice for you about the bus companies:
Sapaco: Tourists get off at Preah Sihanouk Boulevard (around the Olympic Stadium)
Kumho Samco: You have to come 1 hour in advance to print your e-ticket. Tourists get off at Preah Sihanouk Boulevard (around the Olympic Stadium).
Giant Ibis: Buses from Giant Ibis transport depart twice daily.
Ticket price: $20 (almost highest)
Duration: 7 hours
Website: giantbis.com
The Sinh Tourist: You have to come 30 minutes in advance to print your e-ticket. Those buses depart every two hours. The ticket price is about $11. They take 6 hours to get from Ho Chi Minh to Phnom Penh. For more information, visit their website: thesinhtourist.vn.
The Mekong Express: You have to come 30 minutes in advance to change the voucher into ticket and board bus on your smart phone or tablet.
Khai Nam Transport: The duration of these bus is 6 hours. The ticket price is about $9 and the buses depart every hour. The tickets can be booked at website bookmebus.com, you can also go to their website: en.khainamtransport.com for more information.
Phuong Trinh Tourism: The duration is 9 hours. The ticket price is about $12 and the buses depart 4 times per day. For more information, please visit their website: ptbuseline.com.
Virak Bunthan: The duration is 8 hours. The ticket price is about 14$ and the buses depart only once daily.

From Ho Chi Minh to Phnom Penh by Boat

This is an adventurous way to travel from Ho Chi Minh to Phnom Penh even though it’s not the most convenient or cheapest way. You will take a bus from Ho Chi Minh to Chau Doc (Vietnam) then take a boat from there to Phnom Penh.
Hang Chau is the famous company providing speedboat from Chau Doc to Phnom Penh. The boat departs at 7:30 am and takes 4 hours to arrive in Phnom Penh. Additionally, time for formalities is 1 hour. Ticket price is $33, ticket for children from 1 to 3 is fee and from 4 to 8 is half of a normal price. You can pick the boat at Con Tien floating restaurant, Tran Hung Dao Street, Chau Doc town, An Giang Province, Vietnam. If you want to hire a private boat to travel, Hang Chau also offers different kinds of boats for charter: (07 seats, 13 seats, 22 seats, 25 seats). For more information, you can go to their website hangchautourist.vn or contact with the number +84 296 356 2771.
Another luxury choice to travel from Ho Chi Minh City to Phnom Penh is by taking a long cruise tour. Travelling by cruise make you have an overview on the Mekong and get the best service ever. Heritage Line is one of the most reliable company providing such tours. “Pearl of the Orient” is the name of the 4 Days – 3 Nights cruise tour of Heritage Line between Ho Chi Minh City and Phnom Penh. According to the programme of the upstream cruise from Ho Chi Minh City to Phnom Penh, in the first day you will go through Sai Gon – My Tho – Cai Be, in the second day you will go through Cai Be – Sa Dec – Tan Chau, in the third day you will go through Tan Chau- Crossing Boarder – Phnom Penh and stop there in the last day. The price is from $1,000 and depends on the levels and the seasons. For more information, you contact sales@asiajourneytravel.com, or go to the company’s website: http: //heritage-line.com and check the journeys.

From Ho Chi Minh to Phnom Penh by Plane

This is the fastest but the most expensive way to travel from Ho Chi Minh to Phnom Penh. The planes take flight from Tan Son Nhat International Airport (Ho Chi Minh) to Phnom Penh International Airport (Phnom Penh).
The flights take about 45 minutes get from Tan Son Nhat International Airport to Phnom Penh International Airport. You have to spend 15 minutes more for transferring, 3 hours before departure completing the checking procedures. The drive from the Phnom Penh International Airport to the city center takes you another 35 minutes.
The ticket price is from $40 to $120. The cheapest one-way ticket is Vietjet Air’s. The other airlines having the flights from Ho Chi Minh to Phnom Penh are Vietnam Airlines, Cambodia Angkor Air and Qatar Airways.