Considering the growing interest in sustainability reporting and the benefits of sustainability initiatives to developing countries (Ali, Frynas, & Mahmood, 2017), the scarcity of studies on sustainability in developing climes is surprising. This study examines the trend of voluntary sustainability reporting in Africa and the relationship between sustainability disclosures and firms’ financial performance. This paper measures sustainability disclosures using content analysis of the Global Reporting Initiative Guidelines (GRI G4) for total disclosure and the sub-categories of economic, environmental, and social disclosures. Financial performance measures are return on assets (ROA) and return on equity (ROE). Results of the multiple comparison of means do not show any significant improvement in sustainability reporting over the study period. Results of the multiple regression analysis, however, reveal a positive relationship between measures of sustainability disclosures and both ROA and ROE. Additional results show that disclosing firms do not generally have their sustainability reports assured and are from countries with poor sustainability performance. These findings contribute to the literature in reconciling the mixed results from prior studies (Aggarwal, 2013; Al Hawaj & Buallay, 2022) and are useful to the GRI organization in making improvements to their reporting guidelines, particularly as to how the improvements touch African countries.