The aims of the study were to analyse characteristics of the Castanea airborne pollen and to compare aeropalynological data obtained from two sampling stations in north-west Croatia. The study was conducted in Zagreb and Samobor during the 2003-2006 periods, using the seven-day volumetric samplers of the Hirst design. In both study areas, the seasons of chestnut pollination were similar and lasted from June to the end of July, which is comparable to other European cities. A general rule was noticed--the shorter the main pollen season, the higher the pollen peak concentration. Although the pollen season of Fagales pollen is prolonged to summer in the area of inland west-north Croatia due to the genus Castanea summer pollination, the number of days with pollen air concentration higher than 50 per m3 was low and was not likely to have any major effects in allergic individuals. Airborne pollen concentration of Castanea showed positive statistically significant correlation with air temperature and negative non-significant correlation with precipitation. Because of the non-significant differences between the two stations, for a possible long-term forecast model for Fagales airborne pollen for this part of north-west Croatia, aerobiological data obtained from only one station are sufficient.