Malaysia began supporting the MNLF when the group emerged in the 1970s. In recent years, however, the relationship between Malaysia and the MNLF has changed, especially when the MNLF repeatedly expressed negative comments about the Malaysian government. This study aims to explain the shift in the MNLF discourse on Malaysia and the ramifications of this new discourse within the Philippine state. To achieve these aims, this study approaches the issue through the lens of power relations and foreign policy. Moreover, this research employs the analysis of the MNLF’s writings and speeches. Lastly, it argues that the discourse of the MNLF on Malaysia is related to its struggle for legitimacy within the Philippines.