Malaysia lowered its score by 10.67 points to 36.74 points in 2018. A lower score indicates better press freedom.
Malaysia is at the top of the rankings among countries in the South East Asian region, with Indonesia (124th), Philippines (134th), Thailand (136th), Myanmar (138th), Cambodia (143rd), Singapore (151st), Brunei (152nd), Laos (171st), and Vietnam (176th).
The latest index, which was released on Thursday (April 18), takes into account scores and rankings of 180 countries.
The Paris-based organisation said that press freedom received a breath of fresh air in Malaysia, after Barisan Nasional suffered a surprising defeat in the May 2018 general elections.
They said that journalists and media outlets that had been blacklisted, such as cartoonist Zunar and the Sarawak Report investigative news website, have been able to resume working without fear of harassment.
"The general environment for journalists is much more relaxed, self-censorship has declined dramatically and the print media are now offering a fuller and more balanced range of viewpoints, including support for the new ruling coalition led by Prime Minister Mahathir Mohamad, and support for the old ruling coalition, now in the opposition," they said in their 2019 press freedom index report.
They said that while Dr Mahathir had kept his promise to repeal the Orwellian provisions of the anti-fake news law adopted by the outgoing government, the authorities still have a draconian legislative arsenal to suppress media freedom.
This includes the 1948 Sedition Act, the 1972 Official Secrets Act and the 1998 Communications and Multimedia Act.
"Under these laws, which need a complete overhaul, the authorities have strict control over publication licences and journalists can be sentenced to 20 years in prison on sedition charges.
"They pose a constant threat to media personnel, who still cannot express themselves with complete freedom, despite all the progress," they said.
At the top of the rankings are Norway, Finland, Sweden, Netherlands and Denmark, while North Korea, Eritrea and China find themselves at the bottom of the pile.
The degree of freedom available to journalists in 180 countries is determined by pooling the responses of experts to a questionnaire devised by RSF.
RSF said this qualitative analysis is combined with quantitative data on abuses and acts of violence against journalists during the period evaluated.
The criteria evaluated in the questionnaire are pluralism, media independence, media environment and self-censorship, legislative framework, transparency, and the quality of the infrastructure that supports the production of news and information.