Massive amounts of misinformation flood social media like Twitter and Facebook. Digital misinformation includes articles about hoaxes, conspiracy theories, fake news, and other misleading claims. This content has been alleged to disrupt the public debate, leading to questions about its impact on the real world. A number of research questions have been formulated around the ways misinformation spreads, who are its main purveyors, and whether fact-checking efforts can be helpful at mitigating its diffusion. Here we release a large longitudinal dataset from Twitter, consisting of retweeted messages with links to misinformation and fact-checking articles. These data have been collected using Hoaxy (hoaxy.iuni.iu.edu), an open social media analytics platform whose goal is to provide a comprehensive picture of how digital misinformation spreads and competes with fact-checking efforts. The released dataset contains over 20 million retweets, spanning the period from May 2016 to the end of 2017. We provide basic statistics about the data and the associated diffusion networks.