This paper presents the course of poplar pollen season in selected Polish cities in 2018. The measurements were performed in Szczecin, Bydgoszcz, Olsztyn, Bialystok, Zielona Gora, Warsaw, Piotrkow Trybunalski, Lublin, Wroclaw, Opole, Sosnowiec and Cracow. 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. Pollen season of poplar in 2018 started more then 30 days later in comparison to 2014. The pollen season started first in Cracow (March 20th). The highest daily pollen count was recorded in Wroclaw on April 11th (1104 P/m3).