Abstract Background: The extent to which patients perceive and cognitively represent their illness, affords healthcare providers references concerning how they can manage patients' disorders and how will be the outcomes. Aim: Assess the effects of illness perception among psychiatric patients' level of internalized stigma as well as medication adherence. Subjects & Method: Descriptive correlational design utilized with a total number of 191 patients who participated in the study. The Illness Perception Questionnaire Mental Health (IPQ-MH), Internalized Stigma of Mental Illness Inventory (ISMI), and Morisky Medication Adherence Scale (MMAS) were adopted to collect data. Results: patients appeared to have a high level of internalized stigma which is statistically correlated with illness perception. Concerning medication adherence, the results revealed that patients have a high level of compliance. Conclusion: Psychiatric patients vary in their perception of mental illness, some perceived it as a consequence of life stressors and others perceived it as a punishment. Further researches with a comprehensive study of patients' internalized stigma are extremely recommended. Recommendations: Educational campaigns for the public to mend and reform their conceptions and beliefs regarding mental illness also are required.