Bethlehem lies in the center of the Lehigh Valley, a region of 731 square miles (1,893 km²) that is home to more than 750,000 people. The Valley embraces a trio of cities (Bethlehem, Allentown and Easton) within two counties (Lehigh and Northampton), making it Pennsylvania's third-largest metropolitan area. Smaller than Allentown but larger than Easton, Bethlehem is the Lehigh Valley's second most populous city.
There are three general sections of the city, North Bethlehem, South Bethlehem and West Bethlehem. Each of these sections blossomed at different times in the city's development and each contains areas recognized under the National Register of Historic Places.
In July 2006, Money magazine included Bethlehem as one of its "Top 100 Best Places to Live." It placed number 88.
As of the census of 2000, there were 71,329 people, 28,116 households, and 17,094 families residing in the city. The population density was 3,704.4 people per square mile (1,429.9/km²). There were 29,631 housing units at an average density of 1,538.8/sq mi (594.0/km²). The racial makeup of the city was 81.85% White, 3.64% African American, 0.26% Native American, 2.22% Asian, 0.03% Pacific Islander, 9.44% from other races, and 2.56% from two or more races. Hispanic or Latino of any race were 18.23% of the population. The city was named "Pennsylvania's Fastest Growing City".
There were 28,116 households out of which 26.3% had children under the age of 18 living with them, 44.1% were married couples living together, 12.8% had a female householder with no husband present, and 39.2% were non-families. 32.3% of all households were made up of individuals and 14.4% had someone living alone who was 65 years of age or older. The average household size was 2.34 and the average family size was 2.95.
In the city the population was spread out with 21.0% under the age of 18, 14.4% from 18 to 24, 26.6% from 25 to 44, 20.1% from 45 to 64, and 17.9% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 91.5 males. For every 100 females age 18 and over, there were 88.6 males.
The median income for a household in the city was $35,815, and the median income for a family was $45,354. Males had a median income of $35,190 versus $25,817 for females. The per capita income for the city was $18,987. About 11.1% of families and 15.0% of the population were below the poverty line, including 20.7% of those under age 18 and 8.8% of those age 65 or over.
The city is served by Lehigh Valley International Airport, which also serves Allentown, Pennsylvania and the greater Lehigh Valley.