The canton of Vaud registered the most significant rise, from 15.8 requests per day during the period January 1st to February 9th, to 23.3 per day since the referendum, Steve Maucci, head of canton Vaud's population service, told Swiss news agency ATS.
"We noticed some concerns after the vote, even though the referendum didn't concern naturalization," he said.
The canton of Jura also recorded a rise in the number of foreigners requesting information on the naturalization process, reports newspaper 20 Minutes.
In the main, it's those with a C permit — a settlement residence permit obtained after five years in the country — who are concerned about being sent back to their home country if quotas on foreign residents are introduced, according to Jura's naturalization office.
In the canton of Fribourg, "people are frequently asking questions in relation to the February 9th vote," Jean-Pierre Coussa, head of the naturalization service, told ATS.
"They are concerned to know if they will have to leave Switzerland in the future," he said.
Geneva's cantonal office also said more people were requesting information about the naturalization process.
However, the rise could be attributed to discussions in parliament about possible revisions to the naturalization law, reports 20 Minutes, adding that the increase is not reflected in other cantons.
People who have lived in Switzerland for 12 years are eligible to apply for regular naturalization.
The process, which varies depending on the canton and municipality, examines if the applicant is integrated in the Swiss way of life, is familiar with customs and compliant with Swiss law.
Some municipalities require applicants to take a verbal or written naturalization test.
Fees payable to the canton can be up to 2,000 francs ($2,255), with additional municipal and federal fees.