This paper contains an analysis of oak pollen seasons in selected cities of Poland in 2018. Sampling sites were located in the following cities: Bialystok, Bydgoszcz, Cracow, Drawsko Pomorskie, Lublin, Olsztyn, Opole, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, Wroclaw and Zielona Gora. The volumetric method was applied using the Burkard or Lanzoni trap. The pollen season was determined by the 98% method. The season started earliest in Sosnowiec (April 14th). The mean duration of the pollen season was 33 days. The highest pollen concentration (713 P/m3) was observed in Wroclaw (April 19th). The peak values were recorded between April 19th and May 1st in the different cities.