Studies on Ambrosia pollen concentrations were carried out in Lublin in the period [1995][1996][1997][1998][1999][2000][2001][2002][2003][2004]. The effects of a number of meteorological factors were analysed. In the first period of the study, the gravimetric method was used (1995)(1996)(1997)(1998)(1999), while in the second period, the volumetric method was applied. The results show an increasing trend in the amount of airborne pollen. The Ambrosia pollen season in Lublin lasts from August to October. Over a period of 5 years, the highest number of pollen grains was recorded in September (53%), followed by August (44%) and October (3%). There were wide variations in annual totals. The annual total pollen counts was 167-1180 grains, with the peak value in 2002. Maximum daily pollen concentrations (56-312 pollen grains m )3 ) were recorded in the first half of August and in the first half of September. On the days when high Ambrosia pollen concentrations occurred, the temperature was above 21°C and the winds were mainly from the southeast, south and east. Maximum intradiurnal concentrations of pollen grains occurred in the afternoon hours. These results indicate, to some degree, that Ambrosia pollen is transported for long distances before descent.