Authorities say some 27,000 foreign visitors travelled to Iran in the second quarter of 2021 for medical treatment.
That comes as Iran has closed its borders to foreign tourists for one and a half years now due to the coronavirus pandemic.
Iran stopped issuing tourist visas in April, 2020 following the COVID-19 outbreak and the closure of all air and land borders.
However, the country kept issuing visas for trade and medical treatment.
According to figures by the Customs Organisation, well over 4.3 million travellers entered Iran in the year ending March, 2021.
More than three million of them were Iranians and the rest foreign visitors.
With the ban on the issuance of tourist visas still in place as instructed by the National Coronavirus Headquarters, only visitors travelling to Iran for trade and medical treatment are allowed in.