Objective: To measure the prevalence of depression in patients with psoriasis and to evaluate the relationship between the severity of psoriasis and depression and its effect on patients' quality of life. Methods: A total of 154 patients with a confirmed diagnosis of psoriasis were assessed to determine the severity of psoriasis based on the psoriasis area and severity index score, presence, and severity of depression using the patient health questionnaire 9, and quality of life using the dermatology life quality index 10. Pearson correlation coefficient was used to demonstrate the relationship between continuous variables with 95% confidence intervals (CIs); P < 0.00001 was taken to indicate statistical significance. Results: The severity of psoriasis was mild in 36.36% of patients, moderate in 25.97%, severe in 32.47%, and very severe in 5.20%. Of the 154 patients, 139 (90.3%) had depression; the severity of depression was mild in most affected patients (46.7%) and severe in 2.6% of patients. Psoriasis had a moderate effect on the quality of life in 37.01% of patients and a very large effect in 33.77% of patients. The severity of psoriasis was positively correlated with depression (Pearson correlation coefficient, r = 0.42, P<0.00001, 95% CI: 0.28-0.54) and quality of life (r = 0.43, P<0.00001, 95% CI: 0.29-0.55). Conclusion: Depression is a common comorbidity in patients with psoriasis. The severity of psoriasis is positively correlated with the severity of depression and is associated with poor quality of life.