Public sector organizations play an essential role in supporting the government's commitment to sustainable development. These organizations are expected to disclose more social and environmental information than private companies due to public contracts. Malaysian State Islamic Religious Councils (SIRCs) is one of the government agencies responsible for distributing and disseminating adequate and accurate information to various stakeholders, especially the public. These SIRCs frequently organize sustainability-related activities as part of their corporate social responsibility agenda and have a vast potential to contribute by disseminating sustainability-related information on their websites. However, the extent of sustainability website reporting by the SIRCs remained largely unaddressed. Drawing from the literature, this preliminary study proposes a website disclosure index for sustainability reporting by the SIRCs in Malaysia. A content analysis on three SIRCs websites representing three regions in Malaysia have been performed. A total of sixty-seven disclosure items were used as indicators during the website content analysis. Key findings indicate that more effort needs to be initiated by SIRCs in supporting a unified digital reporting that promotes accountability and transparency among government agencies. Nevertheless, the proposed website disclosure index may assist in formulating policies to encourage the use of SIRCs' websites to report sustainability information to the public. This study provides valuable input in supporting the government's aspiration to develop future strategies for achieving Sustainability Development Goals (SDGs) and adds to the limited literature on the website sustainability reporting by the public sector. Future research may use a larger sample of SIRCs to validate the disclosure index proposed in this study.