Linked to deformities in newborn babies of infected mothers, the virus was detected in two travellers who had returned from tropical countries, the federal office of public health said on Tuesday.
The office said it was monitoring the situation but for the moment it is not formally counselling Swiss residents to avoid travelling in countries most impacted by Zika.
But it recommends such travellers protect themselves with good anti-mosquito repellant, to wear long-sleeved shirts and long pants and to sleep under mosquito nets.
The virus, which causes a mild fever, skin rashes and conjunctivitis, spread last year to South America, where it has reached epidemic levels in countries such as Brazil.
Zika is transmitted by the Aedes aegypti mosquito, known to spread other illnesses such as dengue and yellow fever.
The Brazilian government has promised that almost 220,000 soldiers would be deployed to destroy the mosquito population, according to media reports from that country.
But officials fear they are losing the battle and concerns have arisen about the upcoming carnaval in Rio de Janeiro that each year attracts thousands of tourists from around the world.
According to the Geneva-based World Health Organization, the Zika virus is already present in 21 of 55 countries in the Americas.
There is no known cure or vaccine against the virus.
The danger for pregnant women is that the virus can be transmitted to the foetus and possibly lead to congenital malformations (microcephaly) or even death.
But WHO cautions on its website that more investigation is needed to confirm this link.
The US Centers for Disease Control and Prevention have issued a travel alert for people travelling to countries in South America, where the Zika virus is being spread.
The alert warns travellers to take “enhanced precautions” and recommends that pregnant women consider postponing trips to such areas.
Last month the first infection was reported in the Caribbean.