Measurements of NO2 exposure of 29 inhabitants of Erfurt were carried out using personal passive samplers along with stationary passive samplers (indoor and outdoor) at the subjects' apartments and at their work places. The time adjusted results of the stationary measurements were compared with the results of the personal measurements and the differences (mean: 3, 15; max: +47; min: 14, 1 in ppb) were analysed. A multitude of recorded facts (e.g. use of gas stoves, smoking in the apartment) and factors which could not be quantified (e.g under- or over-estimation of the real impact of the pollutant on the person) results in disparities between the personal and stationary measured data. Though people spent 90% of the 48 hours measurement period indoors, time weighted stationary measurements of NO2 cannot replace personal measurements. For evaluation of health problems, lack of well being and work efficiency personal measurements are preferable.