Coxiella burnetii is a bacterium that causes Q fever, a zoonosis that affects large numbers of both humans and animals. From 2007 to 2010, large outbreaks of Q fever were observed in a rural area in the Netherlands. In 2009, field studies were started to investigate if C. burnetii DNA can be detected in aerosols on and in the near vicinity of Q fever affected farms. In 2010, these studies were continued in two areas studied in 2009, in the provinces of Noord-Brabant and Zuid-Limburg, to investigate if C. burnetii DNA was still present in aerosols in these areas. In both areas, the C. burnetii DNA content in aerosols obtained in 2010 seemed to have declined in comparison to data of the same locations visited in 2009. These data are in agreement with the observed reduction in the number of reported Q fever cases in 2010 in comparison to 2009. Possible explanations for this decline could be the start of a mandatory vaccination campaign for small ruminants in 2009 and the culling of pregnant animals on Q fever affected farms that started at the end of 2009. This data will be used in future investigations, in which we will combine molecular detection and typing methods for C. burnetii in aerosols with mathematical modelling to get more insight in the transmission of C. burnetii via aerosols and track (individual) sources for C. burnetii infection.