Urnäsch has a population () of 2,268, of which about 11.6% are foreign nationals. Over the last 10 years the population has decreased at a rate of -3%. Most of the population () speaks German (93.0%), with Serbo-Croatian being second most common ( 2.3%) and Italian being third ( 1.0%). , the gender distribution of the population was 50.6% male and 49.4% female. The age distribution, , in Urnäsch is; 216 people or 9.2% of the population are between 0–6 years old. 316 people or 13.5% are 6-15, and 121 people or 5.2% are 16–19. Of the adult population, 143 people or 6.1% of the population are between 20–24 years old. 651 people or 27.9% are 25–44, and 495 people or 21.2% are 45–64. The senior population distribution is 276 people or 11.8% of the population are between 65–79 years old, and 118 people or 5.1% are over 80.