In Poland, Hornbeam (Carpinus betulus L.) is one of the trees responsible for the symptomes of spring allergy, although epidemiology of sensitivity is not well understood. The aim of this study was to analyse the Carpinus betulus L. pollen seasons in the following cities of Poland: Białystok, Bydgoszcz, Kraków, Kielce, Lublin, Łódź, Olsztyn, Opole, Piotrków Trybunalski, Szczecin, Warszawa i Zielona Góra. Pollen grain was recorded with the standardized volumetric method with the Hirst type traps. The following parameters were included in the analysis: length of the season, peaks of pollen concentration and their date of occurrence, sezonal total values and the numer of days of the pollen concentration above the treshold value that could cause symptoms. The Hronbeam pollen season in 2023 started in the third decade of March or the firts decade of April and lasted until May, for 33.58 days on average. The highest total values were recorded in Szczecin, Zielona Góra, Bydgoszcz, Kraków and Kielce, while the lowest in Bialystok and Lublin. Compared to 2014, the 2023 sesaon was generally charactarized by an earlier start, higher total daily and annual pollen levels.