Businesses have a profound influence on global development in the way they use of natural resources and interact with ecology and social structures. No longer seen only as a part of the problem, but also part of the solution, business are called for to actively pursue the realization of the 2015 Sustainable Development Goals (SDG). Reporting on the SDG outcomes, e.g. in their sustainability reports, is a part of this engagement. While much attention has been devoted to aspects of sustainability reporting, such as determinants and quality, this paper aspires to explore to what extent businesses are disclosing about the SDGs in their voluntary sustainability reporting, using mixed methods. First, using logistic regression, I study the incidence of SDG referencing in sustainability reports published in 2017 of the companies in the Fortune Global 2000 universe and try to correlate these to company attributes such as size and ESG rating.  Second, I study the discourse employed in 40 reports with the highest SDG reference density from 4 regions. Finding that 39.5% of the reports mention the SDGs, only few reports provide substantial disclosure about activities and impacts. There is a strong positive relation with the reporting business being European, have a high ESG rating, issue an integrated report and be a member of the UN Global Compact. While business are coming to terms on how they can effectively report on the SDGs, this study can serve as a baseline to assess future evaluation of the phenomenon.