Pieterlen has a population (as of December 2018) of 4,364.
 As of 2010, 21.4% of the population are resident foreign nationals.
 Over the last 10 years (2000-2010) the population has changed at a rate of 8.5%.
 Migration accounted for 8.1%, while births and deaths accounted for 0.5%.

Most of the population (as of 2000) speaks German (2,832 or 86.3%) as their first language, French is the second most common (116 or 3.5%) and Albanian is the third (95 or 2.9%).
 There are 81 people who speak Italian and 6 people who speak Romansh.

As of 2008, the population was 49.1% male and 50.9% female.
 The population was made up of 1,342 Swiss men (37.9% of the population) and 396 (11.2%) non-Swiss men.
 There were 1,444 Swiss women (40.8%) and 36 (1.0%) non-Swiss women.
 Of the population in the municipality, 847 or about 25.8% were born in Pieterlen and lived there in 2000.
 There were 1,149 or 35.0% who were born in the same canton, while 577 or 17.6% were born somewhere else in Switzerland, and 555 or 16.9% were born outside of Switzerland.

As of 2010, children and teenagers (0–19 years old) make up 20.8% of the population, while adults (20–64 years old) make up 62.2% and seniors (over 64 years old) make up 17%.

As of 2000, there were 1,223 people who were single and never married in the municipality.
 There were 1,603 married individuals, 263 widows or widowers and 193 individuals who are divorced.

As of 2000, there were 444 households that consist of only one person and 88 households with five or more people.
 In 2000, a total of 1,331 apartments (83.9% of the total) were permanently occupied, while 144 apartments (9.1%) were seasonally occupied and 112 apartments (7.1%) were empty.
 As of 2010, the construction rate of new housing units was 26.2 new units per 1000 residents.
 The vacancy rate for the municipality, in 2011, was 4.81%.

The historical population is given in the following chart:
Pieterlen has a population (as of December 2018) of 4,364.  As of 2010, 21.4% of the population are resident foreign nationals.  Over the last 10 years (2000-2010) the population has changed at a rate of 8.5%.  Migration accounted for 8.1%, while births and deaths accounted for 0.5%.
Most of the population (as of 2000) speaks German (2,832 or 86.3%) as their first language, French is the second most common (116 or 3.5%) and Albanian is the third (95 or 2.9%).  There are 81 people who speak Italian and 6 people who speak Romansh.
As of 2008, the population was 49.1% male and 50.9% female.  The population was made up of 1,342 Swiss men (37.9% of the population) and 396 (11.2%) non-Swiss men.  There were 1,444 Swiss women (40.8%) and 36 (1.0%) non-Swiss women.  Of the population in the municipality, 847 or about 25.8% were born in Pieterlen and lived there in 2000.  There were 1,149 or 35.0% who were born in the same canton, while 577 or 17.6% were born somewhere else in Switzerland, and 555 or 16.9% were born outside of Switzerland.
As of 2010, children and teenagers (0–19 years old) make up 20.8% of the population, while adults (20–64 years old) make up 62.2% and seniors (over 64 years old) make up 17%.
As of 2000, there were 1,223 people who were single and never married in the municipality.  There were 1,603 married individuals, 263 widows or widowers and 193 individuals who are divorced.
As of 2000, there were 444 households that consist of only one person and 88 households with five or more people.  In 2000, a total of 1,331 apartments (83.9% of the total) were permanently occupied, while 144 apartments (9.1%) were seasonally occupied and 112 apartments (7.1%) were empty.  As of 2010, the construction rate of new housing units was 26.2 new units per 1000 residents.  The vacancy rate for the municipality, in 2011, was 4.81%.
The historical population is given in the following chart:
Pieterlen