Background: There are many negative stereotypes and beliefs about people who have mental health issues.As a result, those who are suffering from mental illness may have internalized stigma, leading to a worseningofpsychiatricsymptoms. These unfavourable self-perceptions and inadequate coping mechanisms may make it harder to manage the condition and impede patients' attempts to recover and adhere to recommended treatment. Aims: To study the prevalence of internalized stigma and its impact on treatment adherence in patients suffering from depression. Methods: A cross-sectional study was conducted in a tertiary care hospital in north India in the department of psychiatry. Internalized stigma and medication adherence were measured using the ISMI-29 scale and the medication adherence rating scale, respectively. Socio-demographic and clinical details were obtained from 70 consenting patients by using a semi-structured socio-demographic proforma. Results: Most of the patients had a moderate level of internalized stigma, i.e., 52.8%. Based on MARS, it was observed that 77.1% of patients were not adherent to medication. Inrelation to ISMI SCORE, itwas observed that all the domains showed a moderate to good inverse correlation with current medication adherence. This correlation was statistically highly significant.(p<0.05). Out of all the five subscales of ISMI, patients who had absent medication adherence had the highest score in the stereotypic domain (17.59 + 3.84). Patients whose medication adherence was absent had a higher HAM-D score, but it was not statistically significant. Conclusion: The present study suggests that Internalized stigma may play a significant role in determining how well people take their medications, as seen by the correlation between a high level of internalized stigma and lower adherence to medication. There should be Targeted interventions that are feasible and culturally adaptable in order to reduce the burden of internalized stigma among PWMI. In combination with strategies that emphasize raising awareness, strengthening social support, and training programs to empower people with mental illness