Since ancient times, societies have exhibited negative, discriminatory, labeling, and stigmatizing attitudes toward mental disorders and individuals with psychiatric conditions. This situation has negatively affected individuals with mental disorders in many aspects. Over time, individuals with mental illness adopt the stigma they experience and subsequently begin to suffer from internalized stigma. Internalized stigma, or "self-stigmatization," is the adoption of society's negative perceptions-such as being dangerous or inadequate-by the individual with the mental illness themselves. The individual gradually internalizes the prejudices, discrimination, and exclusion present in society. For instance, the societal prejudice that "one cannot be friends with individuals with bipolar disorder" manifests in the patient as "this is true, I cannot be friends with anyone." Consequently, individuals diagnosed with bipolar disorder experience internalized stigma.Psychiatric patients must contend not only with the challenges brought by their illness but also with internalized stigma. Internalized stigma in individuals with mental disorders has detrimental effects on recovery. While experiencing feelings of guilt and shame, psychiatric patients suffering from internalized stigma particularly tend to hide their illness, avoid seeking help for treatment, and face adverse processes regarding treatment compliance. Furthermore, due to the impact of stigmatization, they withdraw from society, experiencing a reduction in social interaction and loneliness. It is well-documented that individuals diagnosed with bipolar disorder experience non-compliance with treatment due to the recurrent and chronic nature of the illness. This situation increases the risk of internalized stigma in patients. Studies demonstrate that patients diagnosed with bipolar disorder experience internalized stigma. Moreover, it stands out as one of the psychiatric illness groups that experiences the highest levels of stigmatization.The management of mental illnesses is a multidimensional framework that requires not only clinical interventions but also the active participation of the patient and social support systems. In this context, psychoeducation is defined as a systematic and evidence-based psychotherapeutic intervention method aimed at informing patients and their families about the disease process, strengthening coping mechanisms, and improving quality of life. Moving beyond traditional approaches, psychoeducation aims to transform the individual and their environment from passive recipients into competent stakeholders in illness management. The fundamental building blocks of psychoeducation comprise medical information regarding the illness, problem-solving strategies, effective communication skills, and the restoration of self-confidence. While these components enable individuals to gain insight into their illness, critical objectives such as managing potential crisis moments and minimizing suicide risk come to the forefront. The literature emphasizes that psychoeducation is one of the most effective supportive methods in preventing relapses and increasing adherence to treatment. Consequently, psychoeducation is a holistic approach aimed at empowering patients and their families by focusing on developing their skills to cope with psychosocial difficulties.Studies have shown that psychoeducation is effective in reducing internalized stigma in patients with bipolar disorder. A quasi-experimental study suggested that psychoeducation reduces internalized stigma and can be implemented in hospitals. A systematic review of individuals with bipolar disorder found that psychoeducation, as a complementary strategy to pharmacotherapy, reduced the frequency of new mood episodes, the duration of hospitalization, and non-compliance with medication. The unique value of this study within the Turkish sample lies in the scarcity of randomized controlled trials (RCTs) examining the specific effect of structured psychoeducation on internalized stigma in patients with bipolar disorder, alongside the inclusion of a three-month post-intervention follow-up test. The purpose of this study is to examine the effect of psychoeducation on the level of internalized stigma in individuals diagnosed with bipolar disorder.