The tax secrecy is intended to protect the confidentiality of an individual's data and prevent their unauthorized publishment. According to the provisions of the Tax Procedure Act, the tax authority is obliged to safeguard the information presented in the tax procedure. The provisions of the Tax Procedure Act prescribe which information is considered tax secret and specify when the obligation of tax secrecy is not violated. In case of a breach of the obligation to keep tax secrecy, criminal and disciplinary responsibility applies. The right to access information is the right of users to seek and obtain information of public character possessed by public authorities. The Act on the Right to Access to Information may limit access to certain information which are tax secrecy. The Information Commissioner is a person who monitors, promotes, and protects the right to access information and their reuse. The Croatian Parliament selects the Commissioner for a term of five years. The Commissioner oversees the implementation of the Act on the Right to Access to Information. This paper consists of three main parts in which tax secrecy, the right to access information, and the case-law of the Information Commissioner that is related to the area of tax secrecy will be analyzed. The goal was to determine when it is and when it is not allowed to access information related to data that falls under tax secrecy.