Many firm level studies rely on readily available databases as COMPUSTAT, based on published balance sheets. While bigger firms are quite reliable described in this data set, small and medium sized firms (SMEs) are not covered, bearing the danger that the conclusions might be biased. To include SMEs into firm-level analysis, the EUKLEED data set for Germany is created. EUKLEED is a comprehensive integrated micro data set on employment, investment, and output for about 1.6 million German establishments, with around 40 million employment cases per year. The data set is combining three sources. The main source (SIS) is a linked employer employee data set (LEED). It supplies firm level information with respect to employment, employment characteristics, labour compensation by type of labour, and establishment characteristics. The remaining two sources are used to calibrate the firm level information on the aggregated data of the National Accounts. Although this calibration is performed for 70 industries and 16 Federal States, EUKLEED has to be applied with care. In the analysis conducted here, it serves merely as a tool for sensitivity calculations.