For electoral purpose, each province or municipality (the highest administrative division) of Vietnam is subdivided into electoral units (đơn vị bầu cử) which are further subdivided into voting zones (khu vực bỏ phiếu).
Vietnam is a unitary state with 58 provinces and 5 municipalities or centrally-controlled cities.
Each province (tỉnh) and municipality (thành phố trực thuộc trung ương) is subdivided into electoral units (đơn vị bầu cử).
Normally an electoral unit within a province or municipality covers about 2 to 6 district-level subdivisions (đơn vị hành chính cấp huyện; which could be rural districts (huyện), urban districts (quận), provincial cities (thành phố thuộc tỉnh) or towns (thị xã)).
Each electoral unit is further subdivided into voting zones (khu vực bỏ phiếu).