Cognitive and sensory deficits were considered a core feature of major depressive disorder (MDD). However, few studies investigated stereopsis integrity in patients with MDD. Thus, the objectives of this study investigated stereopsis integrity and its correlations with cognitive function and depressive symptom in patients with MDD. 90 patients with MDD and 116 healthy controls (HCs) were enrolled in this study. Their stereoacuity was evaluated using the Titmus Stereopsis Test as well as assessing their cognitive function and depressive symptom by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and Hamilton Depression Scale (HAMD). Log seconds of arc was significantly higher in patients than HCs (1.92 +/- 0.41 versus 1.67 +/- 0.16, t = 5.35, p < 0.0001). The percentage of patients with correct stereopsis detection was markedly declined in 400 (z = 3.06, p = 0.002), 200 (z = 3.84, p < 0.001), 140 (z = 4.73, p < 0.001), 100 (z = 4.58, p < 0.001), 80 (z = 5.06, p < 0.001), 60 (z = 4.72, p < 0.001), 50 (z = 4.24, p < 0.001), and 40 (z = 4.85, p < 0.001) seconds of arc compared with HCs. Log seconds of arc was significantly correlated with the RBANS total score (r = -0.38, p < 0.0001), subscores of attention (r = -0.49, p < 0.0001) and language (r = -0.33, p = 0.001) rather than HAMD score (r = 0.03, p = 0.78) in MDD patients. In addition, log seconds of arc was significantly related to the RBANS total score (r = -0.58, p < 0.0001) and language score (r = -0.45, p = 0.006) rather than attention score (r = - 0.30, p = 0.07) in HCs. Further stepwise multivariate regression analyses showed the negative correlation of log seconds of arc with attention score (13 = -0.80, t = -3.95, p < 0.0001) rather than HAMD score (13 = -0.008, t = -0.09, p = 0.93) in MDD patients. However, there was no relationship between log seconds of arc and attention score in HCs (13 = 1.52, t = 1.19, p = 0.24). Our results identified the marked deficits of stereopsis in MDD patients that were tightly correlated with their attention functioning rather than depressive symptom.