This paper presents the course of alder pollination season in Poland in 2019. The measurements were performed in Bydgoszcz, Cracow, Lublin, Olsztyn, Opole, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, Wroclaw and Zielona Gora. Volumetric method with the use of Volumetric Spore Trap (Burkard, Lanzoni) was implemented. Pollen season was defined as the period in which 95% of the annual total catch occurred. The alder pollen season in 2019 started about 20 days earlier compared to 2018. The pollen season started first in Szczecin. The highest daily pollen count was recorded in Wroclaw on February 26th (4266 P/m3