Background <p>This study aims to evaluate the relationships between internalized stigma, insight level, and coping attitudes in remitted schizophrenia and bipolar disorder patients, and to examine the effects of these variables on social functioning.</p> Method <p>This study included 51 patients diagnosed with schizophrenia (SCH) and 45 patients diagnosed with bipolar disorder (BD) who were in remission. Participants were evaluated using semi-structured clinical interviews and the Social Functioning Scale, the Internalized Stigma of Mental Illness scale (ISMI), the COPE Inventory, and the Schedule for Assessing the Three Components of Insight.</p> Results <p>Social functioning, interpersonal communication, and independence competency levels were significantly lower in the SCH group compared to the BD group (<i>p</i> &lt; 0.001). No significant difference was found in internalized stigma. However, there were significant differences in the ISMI total score (<i>p</i> = 0.019) and the subscales of ability to relabel unusual mental events (e, g, hallucinations) as pathological (<i>p</i> = 0.008). Linear regression analysis revealed that years of education (B: 1.983, <i>p</i> &lt; 0.001), high insight (B: 1.772, <i>p</i> = 0.029) and female gender (B: 11.386, <i>p</i> = 0.006) were positively associated with social functioning, whereas a schizophrenia diagnosis (B: -9.916, <i>p</i> = 0.015) and a high level of internalized stigma (B: -0.413, <i>p</i> = 0.013) were negative predictors.</p> Conclusion <p>Years of education, gender, levels of insight and stigma are important variables that affect the social functioning of individuals diagnosed with schizophrenia or bipolar disorder. These factors should be taken into consideration when planning psychosocial interventions.</p>