This degree project examines the international advocacy communication of a Cambodian human rights group during an authoritarian crackdown which began in 2017. Fearing arrests, violence and NGO closures, many rights advocates avoided public statements and protests and focused more on private advocacy towards international actors, seeking foreign interventions to curb government repression. The paper examines how the group advocated towards the international community — using direct lobbying, transnational networks and communication technology — and how key international actors perceived this advocacy. The theoretical framework is based on Karin Gwinn Wilkins’s theory of advocacy communication and is complemented with Nancy Fraser’s and Anastasia Kavada’s concepts of the public sphere and transnational networks. Qualitative data was gathered through semi-structured interviews. A textual analysis was also conducted on an advocacy text to examine how the rights group mediates the power of a global human rights discourse, notably through documenting violations and shaming. The case analysis found that the group effectively used transnational networks and lobbying tactics to access international decision-makers. It also found that advocacy communication was perceived as being effective in terms of attracting the attention of international actors. However, the absence of a fully functioning transnational public sphere for human rights limited its potential impact. The paper recommends future research into claims that Cambodian human rights advocates put too much faith in the ability or will of the international community to influence the human rights situation in their country.