Visa is required for citizens of Hungary to visit Vietnam. Hungarian nationals may have 2 options: Visit Vietnam embassy in Hungary (Budapest) or apply for a visa on arrival to Vietnam from Hungary online. Hungarian citizens may apply for both tourist and business visa to Vietnam for the stay of 1 to 6 months from Hungary. Please check this link for visa fee for Hungarian citizens.

All the information for getting a visa from Vietnam embassy in Hungary can be found here: http://www.vietnamembassy-hungary.org