The aim of this study is to evaluate quality of life (QoL), disability, and psychological well-being (PWB) in patients with disc herniation and stenosis before and after decompressive surgery and to investigate factors associated with an improvement in the postoperative disability level. An observational longitudinal study was carried out to collect preoperative and postoperative data on QoL, disability, and PWB using European Health Interview Survey-Quality of Life (EUROHIS-QoL), WHO Disability Assessment Schedule, second version (WHODAS-II), and Psychological General Well-Being Index-Short (PGWB-S) questionnaires. Friedman’s analysis of variance was performed to compare preoperative and postoperative test scores, whereas a one-sample t-test was calculated to compare the mean test scores with the general population. A hierarchical logistic regression was developed to investigate the association between the change in the disability level after surgery, sociodemographic and clinical characteristics, and preoperative test scores. Complete data were available for 55 patients. PGWB-S and WHODAS-II scores improved significantly (P=0.004 and 0.003), even if the disability level remained high after surgery. The logistic regression showed that patients with worse preoperative WHODAS-II scores had higher odds achieving improvement in their disability level after surgery. This study showed that disability and PWB improve significantly after surgery, but further treatment and a healthy lifestyle are expected and recommended as the disability level remains high. In addition, more severe preoperative disability was a predictor of better clinical outcome.