Voltage in Vietnam is generally 220v with types A C & G sockets - (round pin / flat parallel/or combo of both) adaptors are cheap and readily available locally as many appliances sold here have a mixture euro, chinese various round and flat pun plugs, ( there are notionally some places that still use 110v) but I have not encountered them recently) you don't say what country your from or what equipment you wish to use, this is significant. Most computer/ smart phones chargers and many cameras for example can use either 110/240 volts ( look on the plug pack / transformer ) so will be fine ( by the way 2 pun Australian plugs also will fit into the "D" shaped sockets with a bit of a firm shove)
American hairdryers or other equipment requieing 110v though would be destroyed and should not be used in Viet nam or Cambodia.
"Google " the answer for China and Ukraine don't know but believe china is same as here.
Happy Travels over 5 years agoAnswered by Havenvietnam via WorldNomads.com