An analysis of court verdicts shows one in three of those convicted of a serious sexual offence escapes a prison sentence, according to news reports.
The Federal Statistical Office (FSO) found that in 2015 there were 82 rape convictions. But 26 of those convicted were let off with a conditional sentence.
This means almost one third of rapists were still at liberty.
Figures from 2014 present a similar picture: suspended sentences were handed down to 30 of 105 convicted criminals while 20 were partially suspended.
According to the criminal code, rapists must serve one to ten years in jail. However courts can make custodial sentences of less than two years conditional if they think reoffending is not likely.
Two weeks ago a court in the canton of St Gallen sentenced a man who had raped a 16-year-old girl to a suspended prison term of 24 months and a suspended fine.
The verdict made headlines because of its leniency.
Criminologist Martin Killias says Switzerland is unusual in handing down so many suspended sentences.
“There is no other country in Europe in which people are less likely to be locked up after being convicted of serious crimes like robbery, child abuse, grievous bodily harm and rape,” he told the SonntagsZeitung.
While the government wants to see some violent crimes punished more severely, it sees no need for change in the case of rape, the paper said.