The rate was unchanged from a year earlier, although the actual number of people registered as jobless declined by 0.7 percent (980 people) from May 2013, a report from the State Secretariat for Economic Affairs (Seco) said.
The level of unemployment amongst foreigners fell significantly to 5.8 percent in May from 6.2 percent the previous month, while the rate for Swiss citizens dipped to 2.1 percent from 2.2 percent.
Foreigners accounted for 46.3 percent of joblessness last month.
A total of 130,310 people were registered with regional job placement offices at the end of May, 6,777 fewer than at the end of April, Seco said.
The unemployment rate fell in most cantons, with Obwalden the only one recording an increase (one percent, up from 0.9 percent).
Geneva continued to register the worst record in the country (5.5 percent, unchanged from the previous month), ahead of Neuchâtel (5.1 percent, down from 5.3 percent).
Nidwalden recorded the lowest jobless rate at 0.9 percent, unchanged from the previous month.
The rate fell to 3.2 from 3.3 percent in Zurich, from 2.4 to 2.3 percent in Bern and from 3.6 to 3.4 percent in Basel City.
Valais recorded the biggest percentage decline (to 3.8 from 4.2 percent), followed by Vaud (4.6 percent, down from 4.9 percent) and Ticino (3.8 percent, down from 4.1 percent).
For more information check the full Seco report (available only in German, French and Italian).