Almost all crude oil used in Poland is imported. The domestic production meets less than 4% of needs; therefore, to ensure the security of supplies, Poland relies heavily on imports. It is worth mentioning, however, that Poland has crude oil resources oil fields are located in the Carpathians, Polish Lowlands, and in the economic zone of the Baltic Sea. For years, crude oil is imported mainly from the East, however, a significant change in this approach, leading to an increase in seaborne oil supplies, has been observed in recent years. In 2017, 77.3% of crude oil was imported from Russia, while the rest was supplied from Saudi Arabia, Iraq, Iran, Norway, and Kazakhstan. Increasing the diversification of supplies is, of course, a very positive phenomenon, because it allows reducing the dependence on one supplier, which is beneficial from the point of view of energy security. Taking into account a high dependence on oil imports, the article also discusses important factors affecting the global oil market: low investment in the upstream sector, a drastic decline in oil production in Venezuela, the impact of the U.S. embargo on Iran, or depleting oil reserves.