Most of the population (as of 2000[update]) speaks French (32,804 or 85.8%) as their first language, Italian is the second most common (1,344 or 3.5%) and Portuguese is the third (1,175 or 3.1%).

The historical population is given in the following chart:[6][7] In the 2007 federal election the most popular party was the SP which received 27.76% of the vote.

In the federal election, a total of 10,791 votes were cast, and the voter turnout was 47.3%.

[8] From the 2000 census[update], 11,545 or 30.2% were Roman Catholic, while 10,955 or 28.6% belonged to the Swiss Reformed Church.

[9] During the 2010-11 school year, there were 40 kindergarten classes with a total of 762 students in District de la Chaux-de-Fonds.