Due to human activities a variety of different air pollutants are released into the air. Significant sources of emissions are industry, energy sector and traffic. The traffic sector has different emission sources and is not only related to road traffic. However, while there are many studies that describe the air pollution caused by road traffic, there are only a few studies which describe the emissions released by airports. The Laboratory for Environmental Measurement Techniques of the Düsseldorf University of Applied Sciences performed a case-study to investigate the amount of emissions generated by airport activities. The campaign was carried out during October 2018 for the Environmental State Agency of North-Rhine-Westphalia (LANUV). The aim was to investigate the temporal and the spatial variation of emissions released by the Düsseldorf Airport with a main focus on the release of ultrafine particles (UFP). Therefore, we used a combined strategy in form of stationary and mobile measurements. Additional to the ground-based measurements, a research-aircraft flight was performed in order to investigate the downwind UFP-plume of the airport. ... mehrTwo measurement stations were positioned at the north and south border of the airport to measure the temporal variation of the particle number concentration. These stations were equipped with an SMPS (TSI NanoScan) and a discMini (testo). Additionally, In order to investigate the spatial distribution in the surrounding areas an e-bike was equipped with a discMini (testo), miniWRAS (Grimm/Durag), aethalometer (Aethlabs), cavity-DOAS (IUP Heidelberg), windsonic (Gill instruments), GPS device and a camera. With this e-bike predefined routes were cycled, starting with a full round along the border of the airport. Depending on the actual wind direction, the second part of the route covered areas that were located downwind to the airport. The first results show that the amount of emissions from the airport for species like nitrogen dioxide, soot and coarse particles are on a moderate level. In contrast to that, the amount of ultrafine particles released by the airport resulted in greatly increased values. The data show a typical trend of UFP concentrations, which is characterized by an immediate increase in parallel to the beginning of air traffic in the morning hours, a stay on a high level during the day and a decrease to a typical background concentration level in the late evening, when the air traffic stops due to night flight ban at the Düsseldorf Airport. The wind has a strong influence on the spread of the emissions, so that significantly increased UFP concentrations could be measured up to several kilometers away downwind to the airport. The results of this study indicate that the main part of the UFP emissions is released by the jet engines of the aircraft and the amount of the UFP emissions correlates with the frequency of air traffic.