This paper presents the course of the pollen season of birch in Zielona Gora, Wroclaw, Opole, Sosnowiec, Piotrkow Trybunalski, Warsaw, Cracow and Lublin in 2017. Measurements were performed by the volumetric method (Burkard and Lanzoni pollen samplers). Pollen season was defined as the period in which 98% of the annual total catch occurred. Pollen season of birch in 2017 started more than 4–5 days earlier in comparison to 2016. The earliest onset of the birch pollen season was recorded in Zielona Gora, Wroclaw, Opole and Warsaw – 31st March. The highest daily pollen count was recorded in Wroclaw – 2028 P/m3 (1st April)