The Polish emission reporting system - “Krajowa baza o emisjach gazów cieplarnianych i innych substancji” (or National Emission Database (NED)) - was established at the end of 2010. Initially (data submitted for 2010), the database contained reported emission data for greenhouse gases and air pollutants from plants that have had proper Integrated Pollution Prevention and Control permissions (i.e., integrated permission for the release of gases and dusts into the air). The emissions reported to the NED are recognised as the emissions from local sources and partly as the emissions from point sources, with the possibility of including them into a national emission inventory as point source data (in the case of air pollutants). In the near future, it is planned that the database will be perceived as an integrated system for national air emission management (and the emission data from all sources will be required to pay a “tax for the use of the environment”, which will be regulated by national Polish law). This paper is a part of the work related to the analysis of reported emission data. Additional research on the data collected in the national database might be used to develop a National Emission Inventory, in addition to evolution of country-specific emission factors (e.g. from combustion and industrial processes). The analysed data (emission of NOX, CO, SOX and TSP) were taken from the data for point sources submitted for 2011 primarily with the aim of improving the quality of data submitted previously - for 2010. This paper is the first study in the research to investigate outliers among the reported data using some basic statistical methods.