In response to the increasing ubiquity of social media platforms, improved consumer choice, and technological progress, the importance of consumer-generated content (CGC) continues to grow for organizations marketing their destinations, products, and services to tourists. Yet, despite the importance tourists place on CGC and information shared via social media, there remains a lack of academic focus in this area. To address this gap, we use a rigorous multi-step scale development procedure to create a scale centered on understanding the importance consumers attach to social media sharing (ISMS) from a tourists' perspective. Studies conducted across different contexts (Turkey and Scotland), comprising 1183 participants, were used to validate the newly developed ISMS scale. The scale indicates internal consistency and reliability, alongside construct and predictive validity. Directions for future research and the practical implications of the newly developed ISMS scale are discussed by way of conclusion. •Developed and validated a scale to measure the importance tourists attach to consumer-generated content on social media.•A rigorous mixed method approach was used to develop the scale.•.Scale includes two dimensions: importance attached to i) participant sharing and ii) non-participant sharing•These dimensions bring clarity to customer-generated content classifications.•This newly developed scale is a useful tool for understanding tourists' evaluations of social media content.