Mosogno had a population (as of 2014) of 51.
 As of 2008, 8.6% of the population are resident foreign nationals.
 Over the last 10 years (1997–2007) the population has changed at a rate of -19.2%.

Most of the population (as of 2000) speaks Italian (77.2%), with German being second most common (19.3%) and Spanish being third (3.5%).
 Of the Swiss national languages (as of 2000), 11 speak German, 44 people speak Italian.
 The remainder (2 people) speak another language.

As of 2008, the gender distribution of the population was 54.2% male and 45.8% female.
 The population was made up of 30 Swiss men (50.8% of the population), and 2 (3.4%) non-Swiss men.
 There were 24 Swiss women (40.7%), and 3 (5.1%) non-Swiss women.

In 2008 there was 1 non-Swiss citizen death.
 Ignoring immigration and emigration, the population of Swiss citizens remained the same while the foreign population decreased by 1.
 The total Swiss population change in 2008 (from all sources, including moves across municipal borders) was a decrease of 1.
 This represents a population growth rate of -1.7%.

The age distribution, as of 2009, in Mosogno is; 6 children or 10.2% of the population are between 0 and 9 years old and 3 teenagers or 5.1% are between 10 and 19.
 Of the adult population, 3 people or 5.1% of the population are between 20 and 29 years old.
 8 people or 13.6% are between 30 and 39, 9 people or 15.3% are between 40 and 49, and 14 people or 23.7% are between 50 and 59.
 The senior population distribution is 6 people or 10.2% of the population are between 60 and 69 years old, 2 people or 3.4% are between 70 and 79, there are 8 people or 13.6% who are over 80.

As of 2000, there were 26 private households in the municipality, and an average of 2.2 persons per household.
 In 2000 there were 50 single family homes (or 82.0% of the total) out of a total of 61 inhabited buildings.
 There were 8 two family buildings (13.1%) and 2 multi-family buildings (3.3%).
 There was 1 building in the municipality that was a multipurpose buildings (used for both housing and commercial or another purpose).

The vacancy rate for the municipality, in 2008, was 0%.
 In 2000 there were 74 apartments in the municipality.
 The most common apartment size was the 3 room apartment of which there were 21.
 There were 4 single room apartments and 17 apartments with five or more rooms.
 Of these apartments, a total of 26 apartments (35.1% of the total) were permanently occupied, while 46 apartments (62.2%) were seasonally occupied and 2 apartments (2.7%) were empty.
 As of 2007, the construction rate of new housing units was 0 new units per 1000 residents.

The historical population is given in the following table:
Mosogno had a population (as of 2014) of 51.  As of 2008, 8.6% of the population are resident foreign nationals.  Over the last 10 years (1997–2007) the population has changed at a rate of -19.2%.
Most of the population (as of 2000) speaks Italian (77.2%), with German being second most common (19.3%) and Spanish being third (3.5%).  Of the Swiss national languages (as of 2000), 11 speak German, 44 people speak Italian.  The remainder (2 people) speak another language.
As of 2008, the gender distribution of the population was 54.2% male and 45.8% female.  The population was made up of 30 Swiss men (50.8% of the population), and 2 (3.4%) non-Swiss men.  There were 24 Swiss women (40.7%), and 3 (5.1%) non-Swiss women.
In 2008 there was 1 non-Swiss citizen death.  Ignoring immigration and emigration, the population of Swiss citizens remained the same while the foreign population decreased by 1.  The total Swiss population change in 2008 (from all sources, including moves across municipal borders) was a decrease of 1.  This represents a population growth rate of -1.7%.
The age distribution, as of 2009, in Mosogno is; 6 children or 10.2% of the population are between 0 and 9 years old and 3 teenagers or 5.1% are between 10 and 19.  Of the adult population, 3 people or 5.1% of the population are between 20 and 29 years old.  8 people or 13.6% are between 30 and 39, 9 people or 15.3% are between 40 and 49, and 14 people or 23.7% are between 50 and 59.  The senior population distribution is 6 people or 10.2% of the population are between 60 and 69 years old, 2 people or 3.4% are between 70 and 79, there are 8 people or 13.6% who are over 80.
As of 2000, there were 26 private households in the municipality, and an average of 2.2 persons per household.  In 2000 there were 50 single family homes (or 82.0% of the total) out of a total of 61 inhabited buildings.  There were 8 two family buildings (13.1%) and 2 multi-family buildings (3.3%).  There was 1 building in the municipality that was a multipurpose buildings (used for both housing and commercial or another purpose).
The vacancy rate for the municipality, in 2008, was 0%.  In 2000 there were 74 apartments in the municipality.  The most common apartment size was the 3 room apartment of which there were 21.  There were 4 single room apartments and 17 apartments with five or more rooms.  Of these apartments, a total of 26 apartments (35.1% of the total) were permanently occupied, while 46 apartments (62.2%) were seasonally occupied and 2 apartments (2.7%) were empty.  As of 2007, the construction rate of new housing units was 0 new units per 1000 residents.
The historical population is given in the following table:
Mosogno