Estonia is often considered as a global leader in digital government. However, when it comes to Open Government Data (OGD), Estonia seems to be far behind many other countries according to international surveys and indices. This paper takes a closer look at the puzzle of Estonia’s low OGD maturity against the backdrop of a highly developed e-government by conducting an exploratory case study of Estonia using document analysis, survey data and semi-structured interviews. The results suggest that some of the e-government solutions that have been the key pillars of Estonian e-government success in the past may have become a barrier to understanding and implementing the concept of OGD. However, we are also beginning to see signs of a slowly increasing national OGD capacity thanks to the emergence of an active civic movement driving the development of OGD in Estonia.