The use of “eco‐labels” by businesses, both as communication and positioning strategies, is increasing. For these eco‐labels to be effective, however, it requires consumers to understand and value what eco‐labels are communicating. Research suggests that there are many factors impeding consumers’ understanding of eco‐labels. Most of these studies have focused on single dimensions of a complex phenomenon and in doing so they have ignored the multifaceted aspects of the construct, suggesting that a more integrated representation is warranted. The work herein undertakes four studies to empirically test and validate a multidimensional measure that can be used to assess how consumers psychometrically understand and perceive eco‐labelling. The four‐study process involves qualitative interviews to extend the issues identified within the literature, followed by two studies using principal component analysis, confirmatory factor analysis and structural equation modelling analysis, each using separate samples, to test the reliability and validity of the proposed eight‐dimensional 27‐item ECOLSCALE. Another study is then undertaken to assess the nomological validity of the scale regarding to consumers’ environmental orientation. The ECOLSCALE developed in this work can be used to assist marketers, policy makers and researchers to evaluate the impact of eco‐labelling schemes on consumers’ understanding of eco‐labels, thereby enabling consumers to make more environmentally informed decisions.