Abstract BACKGROUND: Emotional distress and depression are common psychological disturbances associated with low-back and leg pain. The effects of lumbar discectomy on pain, disability, and physical quality of life are well described. The effects of discectomy on emotional distress and mental well-being are less well understood. OBJECTIVE: To assess the effect of microdiscectomy on depression, somatization, and mental well-being in patients with herniated lumbar discs. METHODS: Patients undergoing surgical discectomy for single-level, herniated lumbar disc were prospectively evaluated preoperatively, and at 6 weeks and 3, 6, and 12 months postoperatively. Back and leg pain, depression, somatic perception, and mental well-being were assessed. RESULTS: One hundred patients were enrolled. All were available for 1-year follow-up. Preoperatively, the visual analog scale for low-back pain (BP-VAS), visual analog scale for leg pain (LP-VAS), Zung Self-Rating Depression Scale (ZUNG), Modified Somatic Perception Questionnaire (MSPQ), and Medical Outcomes Short Form-36 mental component summary scale (SF-36-MCS) were 6.3 ± 2.5, 6.3 ± 2.5, 19 ± 11, 9 ± 7, and 4 ± 14. BP-VAS and LP-VAS significantly improved by 6 weeks. Significant improvement in SF-36-MCS was observed by 6 weeks postoperatively, improvement in MSPQ score was observed 3 months postoperatively, and improvement in the ZUNG depression score was observed 12 months postoperatively. No statistical difference occurred during the remainder of follow-up for any outcome measured once improvement reached statistical significance. Eighteen patients were somatized preoperatively, 67% of which were nonsomatized 1 year postoperatively. Ten patients were clinically depressed preoperatively, 70% of which were nondepressed 1 year postoperatively. Improvement in SF-36-MCS, ZUNG, and MSPQ correlated (P < .001) with improvement in BP-VAS and LP-VAS. CONCLUSION: The majority of patients somatized or depressed preoperatively returned to good mental well-being postoperatively. Improvement in pain and overall mental well-being was seen immediately after discectomy. Improvement in somatic anxiety and depression occurred months later. Microdiscectomy significantly improves pain-associated depression, somatic anxiety, and mental well-being in patients with herniated lumbar disc.