Pembina is the oldest community in the Dakotas. A fur-trading post was established on the site of present-day Pembina in 1797 and the first permanent settlement started in 1812. Until 1823, Pembina was thought to be in British Canada, but in that year United States Army Major Stephen H. Long's survey of the 49th parallel revealed Pembina's location south of the Canada – United States border. The first post office in present-day North Dakota was established in Pembina in 1851. Pembina served as county seat from 1867 to 1911.
Pembina is near the northern end of Interstate 29 at the Canada-United States border at Emerson, Manitoba. It is a significant crossing for road traffic headed to and from Winnipeg, Manitoba and is one of three 24-hour ports of entry in North Dakota (the others are Portal and Dunseith).
Pembina is home to the U.S. satellite plant of Motor Coach Industries, which completes assembly of intercity buses, for customers including Greyhound Lines.
As of the census of 2000, there were 642 people, 250 households, and 177 families residing in the city. The population density was 843.1 people per square mile (326.2/km²). There were 274 housing units at an average density of 359.8/sq mi (139.2/km²). The racial makeup of the city was 96.57% White, 0.16% African American, 0.47% Native American, 0.47% Asian, 1.56% from other races, and 0.78% from two or more races. Hispanic or Latino of any race were 1.87% of the population.
There were 250 households out of which 35.2% had children under the age of 18 living with them, 62.8% were married couples living together, 5.2% had a female householder with no husband present, and 28.8% were non-families. 26.8% of all households were made up of individuals and 11.2% had someone living alone who was 65 years of age or older. The average household size was 2.57 and the average family size was 3.12.
In the city the population was spread out with 29.4% under the age of 18, 4.8% from 18 to 24, 29.0% from 25 to 44, 24.0% from 45 to 64, and 12.8% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 98.8 males. For every 100 females age 18 and over, there were 105.0 males.
The median income for a household in the city was $55,536, and the median income for a family was $59,722. Males had a median income of $35,250 versus $26,125 for females. The per capita income for the city was $20,278. About 4.5% of families and 7.7% of the population were below the poverty line, including 12.1% of those under age 18 and 8.2% of those age 65 or over.