Abstract: Freedom of information is a basic requirement of freedom of expression in modern world. The right to freedom of expression is one of the important indicator of human rights. It is noteworthy that both these rights are inherent human rights. Freedom of information is the right of citizens to free access to information held by government institutions. Freedom of information is one of the most important achievements of human rights which is closely related to freedom and transparency of information. The most important effect of freedom of information is the right to free and easy access to information; however, this right is restricted in some cases. Although, recognition of the right to freedom of information is evident in the Iranian legal system, adoption of the law on dissemination and free access to information and its executive regulations can be considered as the first and most serious attempt in this field. By archival review of the written documents, this study addresses FOIA in the light of sustainable development focusing on the law on dissemination and free access to information. Hence, this study first describes the legal nature of FOIA and its role in the Iranian legal system and distinguishes the concept of free access to information from other similar concepts. Then, this study discusses and analyzes freedom of information and its interference with privacy as well as limitations and exceptions to FOIA. Finally, its provisions, strengths and weaknesses as well as its enforcement are overviewed. It is noteworthy that adoption of FOI and its executive regulations, recognition of this right of Iranian citizens and emphasis on duty of the government to provide information to citizens is an important, significant and effective step in paving the way for freedom of information and free access to information.