This study examines the relationship between the level of socioeconomic development of the EU 28 countries and the adoption of International Organization for Standardization (ISO) 14001 environmental management system. First, through a multivariate comparative analysis of the secondary data obtained from the public statistics, a Hellwig’s synthetic indicator is created to rank the level of socioeconomic development of the EU 28 countries. Then, using the total number of certificates issued in 2012 and the increase from 2011, this study has found a correlation between the level of national socioeconomic development and the adoption of ISO 14001 system in their businesses. Although there was no relationship between the number of ISO 14001 certificates in 2012 and the level of socioeconomic development at the national level, a weak negative correlation was observed between the increase of certification from 2011 to 2012 and the level of national socioeconomic development. The results suggest a higher interest in ISO 14001 adoption by the firms from the less developed countries than those from the more developed states.