This was reported by the portal kath.ch (Thursday), citing the latest edition of the "Statistics of Swiss Cities".
According to the Federal Statistical Office, the proportion of people with no religious affiliation has risen sharply since 2000. In the cities, around a third now state that they do not belong to any religion.
"The downward trend affects all religious affiliations and is strongest among the Protestant-Reformed", it continued.
The figures reflect the period from 2000 to 2022, with the decline in some Swiss cities amounting to over 70 per cent in each case, for example in the Zurich airport region.
"100 years ago, a third of the Swiss population lived in urban areas; today it is three quarters," according to one of the findings.
The decline in religious affiliation is explained by this development.
Cities are globalised places that drive social change, they say.
This is reflected, for example, in a bilingual and multilingual population or increasing secularisation.