Most foreigners who have a driver's license issued in their home countries simply have to register for a license here,'says Lam Thanh Trung, vice-chief of the Agency for Granting Driving Licenses (a sub-department of Ho Chi Minh City's Service of Transportation).The agency processes over 100 licenses for foreigners every month,' says Trung. ‘With the required documents, one can have their license registered within seven days.'

Who can get a driver's license in Vietnam:
According to a 2006 mandate by the Ministry of Transportation, all foreigners can register for a license in Vietnam if they had a valid one issued to them in their home countries.

Each city or province's Department of Transportation is in charge of granting driver's licenses for foreigners with licenses issued in their home countries, tourists from neighboring countries driving their own cars in Vietnam, and Vietnamese who acquired a driving license abroad.

However, licenses are only granted to those who have valid travel visas for a period of at least three months in Vietnam (though the actual length of the visit does not have to be that long).

Many tourists make the mistake that it's legal to drive here with an international driver's licence. But they also have to register,' Trung says.

Expiry dates and written exams‘The period for which a [registered] license remains valid is based on the expiry date of one's original license from home,' says Trung.
Standard driver's licenses in Vietnam are good for five years. Motorbike licenses, on the other hand, have no expiry date.'An important point to note, how-ever, is that the type of license issued in Vietnam will only be equivalent to the type granted in one's home country. For instance, ‘A four-wheel driver's license can-not be registered to ride a motorcycle,' Trung stresses. Those who have a four-wheel license but want to ride a motorcycle will have to pass an exam on riding techniques, but won't have to take a written exam on traffic laws. To begin, a form requesting a license must be obtained (see below) and filled out by any one of the following: the Vietnamese Embassy, the Consulate General, the Representative Office of International Organization in Vietnam, the Ministry of Foreign Affairs, Department of Planning and Investment or the General Director of Joint-Venture and Foreign-Capital Companies. A valid pass-port will also be required.

Overseas Vietnamese will need to have their documents completed by the Committee for Overseas Vietnamese.

What is requided

The following submissions are required for a foreigner to get a driver's license in Vietnam:
1 petition (issued form) requesting driver's license
1 copy (notarized duplicate) of original driver's license
1 Vietnamese-translated copy (notarized duplicate) of driver's license
1 copy (duplicate) of passport 3 passport-sized photos
Original copies of passport and driver's license must be shown when submitting all documents
Forms to request a driver's license can be obtained at the Agency for Granting Driver's Licenses or sgtcc.hochiminhcity.gov.vn
In Ho Chi Minh City, all documents must be submitted to the authorities for driver's license registration, located at: 252 Ly Chinh Thang Street, District 3, 8 Nguyen Anh Thu Street, District 12.

Above is what you need If you're planing to rent a bike and travel alone then yes you must be a licensed rider and your motorcycle must be licensed as well. However, the riding license will not required if you take a guided motorcycle trip from a local motorcycle tour-operator as they're in charge of solving this problem.