Adult survivors of childhood sexual abuse (CSA) may experience emotional, social, and psychological difficulties, heightened due to the interpersonal nature of harm. Despite the demonstrated effectiveness of trauma-focused treatments in the West, a culturally specific understanding of the needs of and treatments for survivors in South Asia is still in its infancy. The study aimed to systematically review research findings on the mental health impacts of CSA on adult survivors and current treatment approaches and their efficacy and acceptability in South Asia. Seven databases (Scopus, Ovid, CINAHL, ProQuest, EThOS, Google Scholar, and Dogpile) and five peer-reviewed South Asian journals were searched from inception until March 30, 2023. Searches included participants who were adult survivors of CSA of South Asian origin residing in South Asia. Studies on their mental health, different treatments, and the efficacy and acceptability of these treatments were included. Quality assessment tools were used to appraise the quality of included studies. The results were synthesized narratively. A total of 3,362 records were retrieved, and 24 articles were included in the final review. Twenty studies reported mental health impacts of CSA on adult survivors, four studies reported current treatments offered, and two studies were on recovery. However, no study focused on the efficacy or acceptability of the treatments being delivered. Even though the needs of adult CSA survivors in South Asia have been partly identified, there is very little research into the treatments for them.