The aim of this study was to evaluate the effects of levomilnacipran extended-release (ER) on depression-related fatigue in adults with major depressive disorder. Post-hoc analyses of five phase III trials were carried out, with evaluation of fatigue symptoms based on score changes in four items: Montgomery-Åsberg Depression Rating Scale (MADRS) item 7 (lassitude), and 17-item Hamilton Depression Rating Scale (HAMD17) items 7 (work/activities), 8 (retardation), and 13 (somatic symptoms). Symptom remission was analyzed on the basis of score shifts from baseline to end of treatment: MADRS item 7 and HAMD17 item 7 (from ≥2 to ≤1); HAMD17 items 8 and 13 (from ≥1 to 0). The mean change in MADRS total score was analyzed in patients with low and high fatigue (MADRS item 7 baseline score <4 and ≥4, respectively). Patients receiving levomilnacipran ER had significantly greater mean improvements and symptom remission (no/minimal residual fatigue) on all fatigue-related items: lassitude (35 vs. 28%), work/activities (43 vs. 35%), retardation (46 vs. 39%), somatic symptoms (26 vs. 18%; all Ps<0.01 versus placebo). The mean change in MADRS total score was significantly greater with levomilnacipran ER versus placebo in both low (least squares mean difference=-2.8, P=0.0018) and high (least squares mean difference=-3.1, P<0.0001) fatigue subgroups. Levomilnacipran ER treatment was effective in reducing depression-related fatigue in adult patients with major depressive disorder and was associated with remission of fatigue symptoms.