Background: Substance use disorder is a chronic disease. Managing it after rehabilitation requires lifestyle changes, regular therapist visits and, from time to time, changes in treatment plan, Lifestyle typically reflects an individual's attitudes, way of life, values, or world view. Therefore Lifestyle is the key ingredients that make up a person's health and wellbeing, including (but not limited to) relationships, employment status and accommodation. Aim: This study aimed to assess a Lifestyle of patients with substance use disorder. Design: A descriptive study design was utilized to achieve the aim of this study. Setting: The study was conducted in the outpatient addiction clinic at Al- abbasia Mental Health Hospital. Subject: A purposive sample of 50 adult patients. Tools of data collection: 1) A structured interview questionnaire 2) Semi-structured interview for the brief psychiatric rating scale 3) The substance use disorder patients' lifestyle questionnaire. Results: The results of this study showed there were unsatisfied lifestyle dimensions (diet, sleep exercise and dealing with pain, anger, problems and relationships and effective communication the work environment) among patients with substance use disorder. Conclusion: The current study concluded that unsatisfied lifestyle among patients with substance use disorder. Recommendations: The current study recommended that, Establishing life style modification programs in hospitals, focusing on both short and long-time care for patient with substance use disorder.