Abstract In recent years, natural gas quality has become a contested topic for market partners along the gas value chain, especially in the context of the European gas quality harmonization process. While a consensus could be achieved on many aspects of gas quality regulation, leading to a first European standard for H-gas quality (EN 16726), this standard lacks any regulation of combustion-related properties except for a minimum Methane Number. There is also significant uncertainty to what extent gas quality variations actually occur in German gas grids today and how they may affect gas-fired applications. This was the focus of two surveys carried out by a group of German gas-related research organizations in which gas quality measurements over long periods of time were compiled for various regions in Germany to highlight frequency and severity of local gas quality and composition changes. While one of these studies concentrated on the glass industry and also looked at possible measures to compensate for gas quality fluctuations, the other took a broader view, investigating common adjustment practices, awareness of gas quality issues among operators of gas-fired equipment and typical countermeasures by a statistical analysis of all sectors of German gas utilization (domestic, chemical and thermal processing industries, power generation). It appears likely that these findings can be transferred to other countries to a certain extent. The results of these studies as well as background information on the European gas quality harmonization process will be the focus of this contribution.