New significant clinical studies suggest the enormous preventive and therapeutic capabilities of Urtica dioica L. Despite being already known as multi-purpose plant, it is still underestimated and relatively poorly researched in regards to its allergenic potential. The aim of the study was to compare nettle pollen season in 2023 in ten cities located in different regions of Poland: Bialystok, Kraków, Kielce, Lublin, Olsztyn, Piotrków Trybunalski, Szczecin, Warszawa, Wrocław and Łódź. Nettle pollen grains were collected using Burkard or Lanzoni Hirst-type volumetric samplers. The 95% method was used to determine the duration of the pollen seasons. The nettle pollen season in 2023 began in June. The earliest onset of the pollen season was recorded in Kielce (June 15th), in Wrocław (June 16th) and Warszawa (June 17th). In most of the monitored cites maximum daily pollen concentrations were registered in the middle of September. Mean seasonal pollen index (SPI) reached the value of 8579. The highest total values (SPI) were in Lublin (14,387) in Kielce (13,424) and in Wrocław (12,304). The lowest total values level (SPI) was in Białystok (3434) and in Łódź (4935). But in Łódź in October 2023, thanks to favourable weather, many Urtica dioica L. plants bloomed again. Unfortunately, aerobiological research was no longer carried out at that time.