Quotas on the number of EU citizens working in Switzerland are now in force for one year.
The government in Berne says immigration has now reached unacceptable levels, with foreigners making up a quarter of the population.
The Swiss have made a series of deals with the EU on the free movement of people in return for access to European markets.
The European Commission has warned that the quotas could jeopardise relations.
A recent government statement said the number of people arriving in the country exceeded the number leaving by up to 80,000 in recent years.
The government is under pressure from the People's Party and the Green Liberal Party, which say immigration has reached unsustainable levels.
The BBC reports the majority of immigrants to Switzerland come from EU countries like Germany, Spain, Portugal and Italy.
Correspondents say Portuguese seeking work will be hardest hit by the new rules.
From 1 June, immigrants from Estonia, Hungary, Lithuania, Latvia, Poland, Slovakia, Slovenia and the Czech Republic will have the number of long-term residence permits capped at 2180.
From the same date, long-term residence permits for the 17 older EU states will be capped at 53,700 for 12 months.
Immigration to Switzerland from Bulgaria and Romania is severely restricted.