Background: Lumbar degenerative disc disease (LDDD) is a significant cause of disability that impacts negatively on the quality of life (QoL) of patients. Most times, the surgeon’s view of successful lumbar decompression does not correlate with patient’s satisfaction. Patient-reported outcome measure becomes necessary in assessing the efficacy of lumbar decompression and hence patients’ satisfaction which reflects on the QoL. EQ-5D-5L is a universally accepted QoL instrument and was deployed in this study to assess the improvement in QoL after lumbar decompression. Objectives: The study assessed the preoperative and six months postoperative QoL after lumbar decompression in patients with severe LDDD using EQ-5D-5L instrument and determined how preoperative motor deficit and radiological lumbar spine instability affected patient’s QoL after lumbar decompression. Methodology: It was a prospective, longitudinal study carried out in Memfys Hospital, Enugu. The study sample included 56 consenting patients aged 31 to 80 years, who presented to the hospital for operative treatment of LDDD and met the study criteria. The preoperative QoL was evaluated using the EQ-5D-5L instrument and compared to the scores six months after surgery. The effect of preoperative motor deficit and lumbar spine instability, when present, on QoL after surgery was also assessed. Patients with spinal deformity, previous lumbar spinal surgery, traumatic spinal cord injury or co-existing severe cervical degenerative disease were excluded from the study. Results: The mean EQ-5D score increased from 0.45 to 0.71 (p < 0.001) while the mean EQVAS increased from 48.84 to 67.86 (p < 0.001) six months after surgery. The rate of agreement between the VAS and dimensional scoring of the instrument was 90.2%. Pain/ discomfort was the most significant dimensional predictor of QoL. The mean increase in EQ-5D score in patients with and without preoperative motor deficit was 0.258 and 0.257 respectively (p = 0.978) while the mean increase in EQ-VAS in patients with and without preoperative motor deficit was 21.458 and 17.188 respectively (p = 0.435). In the same vein, the mean increase in EQ-5D score in patients with and without preoperative lumbar spine instability was 0.216 and 0.274 respectively (p = 0.376) while the mean increase in EQ-VAS score in patients with and without preoperative lumbar spine instability was 15.00 and 20.49 respectively (p = 0.435). Conclusions Patients with LDDD had significant improvement in QoL at six months following lumbar decompression. Preoperative motor deficit or lumbar spine instability did not significantly impact QoL. Keywords Quality of life, EQ-5D-5L, LDDD, lumbar decompression