RSF ranked Iran at 164 out of 167 in its 2005 annual Press Freedom Index.
Iran (164th) once again has the regions worst record of press freedom, with seven journalists in prison and four others provisionally free and in danger of being returned to jail at any moment, the top media watchdog said.
It highlighted the cases of dissident journalist Akbar Ganji and cyber-dissident Mojtaba Saminejad, who are both currently serving prison terms.
The international press freedoms group frequently criticised media censorship and violation of journalists rights in Iran.