Of the population in the municipality, 92 or about 27.8% were born in Zielebach and lived there in 2000. There were 109 or 32.9% who were born in the same canton, while 102 or 30.8% were born somewhere else in Switzerland, and 20 or 6.0% were born outside of Switzerland.
, the population was 48.1% male and 51.9% female. The population was made up of 148 Swiss men (46.0% of the population) and 7 (2.2%) non-Swiss men.