The union federation said the concept of equal pay for equal work is far removed from the daily reality of most women in Switzerland.
"When it comes to pay, being a woman is catastrophic," said SGB President Paul Rechsteiner in Bern.
"Men earned on average 6,427 francs while women earned 3,745 francs per month" he added, referring to take-home wage rates from 2008. "That's 41.7 percent less."
He said the reason behind this enormous difference was the fact that women perform a much larger amount of work than men that is important for society overall, but unpaid. Correspondingly, their overall earnings tend to be lower when it comes to gainful employment.
This difference between the amount of paid versus unpaid work done by the two sexes is especially detrimental to women in cases of separation or divorce.
According to the union, many more women work in the low-wage sector than men. Around 75 percent of low-wage jobs are held by women.
Rechsteiner said that wage discrimination was a serious problem in Switzerland, and that women generally earned about 10 percent less than men for equal work.
He said it was especially alarming that such discrimination had actually gotten worse over the past few years.
"It can't go on like this," he said.