BACKGROUND: Cognitive Behavioral Therapy (CBT) has been proven an effective treatment for anxiety disorders. However, CBT still dominantly uses concepts and constructs rooted in Western cultures, and most research focuses on Western populations. It is unsure how this translates to non-Western cultures like Southeast Asia. AIMS: Our objective is to explore which types of cultural adaptations in CBT have been implemented for anxiety disorders in Southeast Asia and their effectiveness. METHODS: We systematically searched PubMed, PsycINFO, Embase, CENTRAL, GARUDA, and Google Scholar for CA-CBT for anxiety disorders in local communities in Southeast Asian countries. Data were analyzed using a narrative approach distinguishing between peripheral and core component adaptations. PROSPERO database preregistration number was CRD42022336376. RESULTS: Seven studies (one randomized controlled trial, three quasi-experimental studies, and three case reports) were selected. Two studies made cultural adaptations in multiple components. Two studies modified core treatment components by incorporating local values in the CBT restructuring process. Three studies conducted cultural adaptation on peripheral treatment components: adaptation to materials and semantics, cultural examples and themes, and session structure. Three studies did not provide detailed information. One RCT study showed better improvement for those who got CA-CBT than those in treatment as usual (TAU). CONCLUSION: The findings suggest some components to consider when conducting cultural adaptation. We could not establish the degree of superiority of CA-CBT over non-CA-CBT nor identify components with the most influence due to the limited number of studies found. Employing standard documentation in reporting trials is also important to increase transparency.