Abstract: Background and Aim: Mental health of non-hospitalized patients and those with non-severe infections has attracted lower attention in comparison to other patients. Circulating monocytes are deeply involved in all stages of COVID-19 infection. The present study aimed to investigate the relationship between monocyte-to-lymphocyte ratio (MLR) and depressive symptoms in patients with non-severe COVID-19 infection. Patients and Methods: The study included 312 patients with non-severe COVID-19 infection diagnosed on the basis of a positive reverse-transcriptase polymerase chain reaction (RT-PCR) test of nasopharyngeal swabs. Depressive symptoms were assessed using the validated Arabic version of the 7-item Hamilton Depression Rating Scale (HAMD). According to the obtained scores, patients were classified to have mild (10-13), moderate (14- 17), or severe depression (>17). Results: The present study included 312 patients with non-severe COVID-19. According to HAMDS, clinically significant depression was diagnosed in 144 patients (46.2 %). They comprised 38 patients (12.2 %) with mild depression, 30 patients (9.6 %) with mild-tomoderate depression and 76 patients (24.4 %) with moderate-to-severe depression. Multivariate logistic regression analysis identified male sex [OR (95% CI): 2.07 (1.27-3.36), p = 0.003], presence of dyspnea [(OR (95 % CI): 1.99 (1.21-3.27), p = 0.007], D dimer levels [OR (95% CI): 2.32 (1.19-4.52), p = 0.013], MLR [OR (95% CI): 0.52 (0.28-0.99), p = 0.046] and abnormal CT findings [OR (95% CI): 1.79 (1.08-2.95), p = 0.023] as significant predictors of depression in the studied patients. Conclusion: Low MLR is related to depressive symptoms in patients with non-severe covid-19 infection. Other predictors include male sex, dyspnea, abnormal CT findings and elevated D-dimer levels.