As of the census of 2000, there were 46,809 people, 19,490 households, and 13,272 families residing in the township. The population density was 2,460.1 people per square mile (949.7/km²). There were 20,355 housing units at an average density of 1,069.8/sq mi (413.0/km²). The racial makeup of the township was 73.58% White, 24.24% African American, 0.13% Native American, 0.54% Asian, 0.01% Pacific Islander, 0.34% from other races, and 1.15% from two or more races. Hispanic or Latino of any race were 0.63% of the population. The Italian American population is very numerous in the township.
There were 19,490 households out of which 26.3% had children under the age of 18 living with them, 51.1% were married couples living together, 13.5% had a female householder with no husband present, and 31.9% were non-families. 28.2% of all households were made up of individuals and 13.2% had someone living alone who was 65 years of age or older. The average household size was 2.38 and the average family size was 2.91.
In the township the population was spread out with 21.7% under the age of 18, 6.3% from 18 to 24, 27.0% from 25 to 44, 25.3% from 45 to 64, and 19.7% who were 65 years of age or older. The median age was 42 years. For every 100 females there were 88.6 males. For every 100 females age 18 and over, there were 84.0 males.
The median income for a household in the township was $39,960, and the median income for a family was $46,971. Males had a median income of $36,143 versus $27,331 for females. The per capita income for the township was $20,161. About 5.6% of families and 7.5% of the population were below the poverty line, including 10.8% of those under age 18 and 6.2% of those age 65 or over.
Interstate 376 runs through the southernmost part of Penn Hills as route linking to other eastern suburbs, as well as Downtown Pittsburgh.
Pennsylvania Route 791, more commonly referred to as Rodi Road, connects heavily-traveled Frankstown Road (at PA-791's northern terminus) with I-376 at its southern terminus. Numerous restaurants, fast food locations, stores, gas stations, and hotels can be found on Rodi, as many truckers/travelers using I-376 use the Penn Hills exit to refuel, or even stay overnight.
For air travel, Pittsburgh International Airport, located in the western portion of the county is most commonly used. However, the Allegheny County Airport in West Mifflin is also still in use.
Several bus lines of the Port Authority of Allegheny County offer service to Downtown Pittsburgh, and the Port Authority also has several routes and "flyers" located in Penn Hills.