Background and objectives: Symptomatic ASD after lumbar spinal fusion surgery occurs most commonly in the cranial segment. The surgery for ASD contains anterior lumbar interbody fusion, posterior lumbar interbody fusion, decompression alone (laminotomy) and so on. But coblation nucleoplasty for ASD has not been reported previously. In this study, a case of coblation nucleoplasty after posterolateral fusion surgery at L4-L5 for adjacent segment degeneration (ASD) was reported and the clinical results were examined. Material and method: A 32-year-old male patient who had discectomy and fusion on the L4-L5 level seven years ago complained of chronic back pain for four months with numbness on his right leg for a month. X-ray revealed mild lumbar instability on L3-L4 segment. Magnetic resonance imaging confirmed a right-sided L3-L4 herniated disc compressing the L4 nerve root. He underwent L3-L4 coblation nucleoplasty. The visual analog scale (VAS) was adopted to assess the relief of back pain, leg pain and numbness. Results: The operation was performed successfully and the symptoms were relieved significantly at the follow-up of more than twenty-four months. Conclusion: Although coblation nucleoplasty is not a regular therapy for ASD, the excellent outcome of this case suggests that this technique might be an option before a complicated revision surgery.