The use of corporate websites as communication medium may contribute to good governance and specifically transparency as one of the basic principles of governance, mitigating the effect of the agency problem. The primary objective of this study was to ascertain the link between voluntary corporate website disclosure and information asymmetry for the smallest JSE-listed companies. Rule 26, as issued by the LSE for its AIM-listed companies, was used as proxy for disclosure while the bid-ask spread stood as a proxy for information asymmetry. The results of a content analysis showed that the majority of smaller listed JSE companies are not on par with their UK counterparts. Using agency theory, it was argued that if information voluntarily disclosed by companies on their corporate websites is useful to investors, it should theoretically decrease information asymmetry. Although empirical evidence of a negative relationship between disclosure and the bid-ask spread was found, the relationship changed to not significant once controlled for market capitalisation. Besides the bid-ask spread, the association between disclosure and both share price volatility and share turnover (both as alternative proxies for information asymmetry) was tested, and both were found non-significantly related to disclosure. The results reported do suggest that the Rule 26 minimum corporate website disclosures may not be sufficient in persuading investors to change their trading behaviour. Although there has been no research on the voluntary compliance and effect of Rule 26 website disclosure on information asymmetry using JSE small-cap data, a major limitation of this study is that generalisation of results is limited to small listed companies.