Abstract Depression and anxiety have a significant role in human well-being, quality of life, morbidity and mortality. It have negative impact on self esteem and ability to perform daily tasks. Bariatric surgery is gaining popularity since it delivers effective long-term weight loss, also improving physical, medical, and emotional health. The effect of Bariatric surgery on depression and anxiety varies between patients. This study aimed to measure the prevalence of depression, anxiety and its related risk factors among post-bariatric patients in the kingdom of Saudi Arabia. A web-based cross-sectional study was conducted among 406 adults who underwent bariatric surgery. Two validated screening tools for depression and anxiety were applied in this study; Patient Health Questionnaire-7 (PHQ-9), and Generalized Anxiety Disorder-7 questionnaire (GAD-7). Regarding depression prevalence, 36.2% of the participant ranged from moderate depression to severe depression. Regarding anxiety prevalence, 22.1% of the participant had moderate to severe anxiety after bariatric surgery. Logistic regression for significant factors of depression displays that, nationality, time since the surgery performed and complication after surgery were significant predictors for depression (p≤0.05). The significant predictors for anxiety were age, time since the surgery performed and complication after surgery (p≤0.05). This study concluded that a significant proportion of patients had varied degrees of depression and anxiety after bariatric surgery. Longer time since surgery performed and complication after surgery were significant predictors for depression and anxiety as well, so more psychiatric follow up was recommended.