PKN Orlen bought a cargo of Iranian crude for November 24-25 loading dates, sources were quoted as saying by Platts.
The Suezmax Delta Poseidon has been placed on subjects on a Kharg Island to Gdansk, according to shipping fixture reports.
Poland is heavily reliant on Russian Urals crude but the country's two refiners are slowly beginning to diversify their crude supplies.
Russian exports from the Primorsk oil terminal, where the bulk of the Urals program usually loads, have been down sharply this month due to scheduled maintenance.
Sources said this along with reduced flows of Iraqi crude into Europe, are increasing spot demand for sour crudes from the Middle East into Europe.
The last time Poland purchased Iranian crude was earlier this year, when the Vilamoura tanker discharged Iranian oil in mid-January.
In July 2016, Grupa Lotos bought spot cargoes of Iranian light crude from Iran's National Iranian Oil Co. (NIOC).
In late October, PKN Orlen bought its first shipment of US crude, the first to Poland since the US ended its embargo on exports in December 2015.
PKN also occasionally buys spot cargoes from Iraq, Azerbaijan, Kazakhstan, Nigeria and Norway.
Meanwhile, Trend News Agency reported that a governmentally organized group from Poland has successfully engaged some 90 Polish companies in talks with Iranian partners in hope to promote trade ties between the two countries.
The Go Iran Program was launched one year ago by the Polish Ministry of Economic Development in order to promote Polish entrepreneurs, Agnieszka Schutte, the program head told Trend News Agency on the sidelines of IAPEX 2017: Iran Auto Parts Exhibition in Tehran.
"We provide info on certificates and attending exhibitions. This exhibition is our first business mission to Iran and in future we would like to organize at least two business missions, as well as conferences and business forums for Polish and Iranian entrepreneurs," said Schutte, who heads the National Marketing Unit of the Polish Investment and Trade Agency.
"Also we have official delegations from Iran and are engaged in cooperation with the Iranian embassy and the Polish-Iranian chamber of commerce, as well as Iranian institutions to promote trade ties."
Jaroslaw Kaczynski, the head of Tehran Bureau at the Polish Investment and Trade Agency, also said the group is preparing a general plan for promoting Polish industry and economy in Iran and the other way round.
"Some time ago we started a process to designate certain fields of industries between our two countries which have the biggest opportunities for both sides," he said.
One of those fields is auto parts, Kaczynski said.
"There are plans being prepared for next year. It is a platform for Polish companies to apply for and attend exhibits, conferences, and meetings. We work as a non-profit organization."
Kaczynski noted that five companies were selected from Poland for the 2017 Tehran Auto Parts Exhibition.
"One of these companies here now specializes in components for LPG and CNG engines. Another company specializes in storage units for tires and all their spare parts in storage houses. Yet another one produces equipment for any kind of harvesting machines, snowplows, etc. The next one produces bearings for cars, trucks, etc. Here we provide these businesses with some place to talk, hold meetings, and so on."