Since Sunday the health ministry in the oil-rich Gulf state began implementing the measure, described by activists as racist, at the public hospital in Jahra, west of Kuwait City, on experimental basis for six months.
If successful, it will be expanded to other public hospitals as per a decision issued last month by Health Minister Mohammad al-Haifi, who is a well-known surgeon.
As per the measure, foreign residents will be able to receive treatment at the outpatient clinics of public hospitals in the evenings only.
The measure "is intended to ease overcrowding at clinics" where the number of patients has been increasing rapidly, the health ministry said in a statement sent to AFP.
It cited the health minister as stressing that the ministry will continue to provide "the best health care for citizens and expatriates," adding that hospitals will provide all other medical services and emergencies to all citizens and residents at all times.
The minister also said that a new 1,100-bed hospital under construction will be completed in the near future to solve the overcrowding problem.
"Kuwait is a multi-cultural society that brings people from all over the world and provides them with the best healthcare," said Haifi.
The decision was taken following complaints in the pro-government parliament that Kuwaiti patients have to wait for long at public health facilities because of the large number of expatriates.
Kuwait is home to 2.6 million foreigners, mostly from India, Pakistan, Bangladesh, the Philippines, Egypt and Syria, and 1.2 million native Kuwaitis.
Kuwait provides free medical services to citizens but expats must pay an annual fee of $175 each besides paying reduced charges for certain procedures like x-ray.
Similar restrictions are in place at other government agencies such as the traffic department, which handles applications from expats only in the evening.
Kuwait has also over the past two months deported hundreds of expatriates for traffic offences.