Despite the effort done by member states during the last decade, failure in the implementation of the Ambient Air Quality Directive is being continuously registered in many European cities for different air pollutants. One of the biggest concerns in Bulgaria is the exceeded PM10 concentration in the ambient air, measured in all six air quality zones during the winter period. This has induced numerous activities (at the national and European level) focused on the following issues: identification of the level of exceedance of the air quality norms for PM10; the general emission sources; the most prominent omissions and discrepancies in the legislative framework; the level of implementation of the prescribed measures and many others. However, the PM10 exceedance is still of a significant concern in at least 28 municipalities in Bulgaria. Thus, the present work introduces a brief report on the current state of the problem in the country. For that purpose, benchmarking analyses was applied for obtaining the range of discrepancies and the tendencies of the PM10 concentrations, monitored in the ambient air at the affected municipalities. The investigation was carried out using merely officially reported and freely accessible data and covered a relatively short period of time of six years. The latest national and European environmental reports present data confirming the primary role of residential heating and transport during the winter period as well as at the occurrence of particular atmospheric conditions.