A 79-year-old woman was presented to our hospital with L3 radiculopathy due to excessive osteophyte formation following an osteoporotic vertebral compression fracture (OVCF). She underwent a unilateral biportal endoscopy (UBE)-assisted canal decompression via the interlaminar approach. The operation time was 101 minutes. Good results were observed at one-year postoperatively. We found that UBE may be useful to avoid the risks of facetectomy, especially when decompressing narrow interlaminar spaces after upper lumbar compression fractures. Improvement of radiculopathy after lumbar compression fractures remains challenging because the upper lumbar vertebrae are often affected by compression fractures. Even in normal cases, the interlaminar space can be narrow; furthermore, the space becomes narrower after compression fractures due to vertebral body collapse. When there is compression of the posterior wall nerve root due to thickening of the yellow ligament and posterior wall damage, decompression is needed to obtain a sufficient working space. With the UBE technique, the endoscope and portals are independent of each other, and the field of view and instrument can be moved separately. Therefore, in the upper lumbar spine with a narrow interlaminar space following OVCF, decompression can be achieved while avoiding the risk of facetectomy and is unnecessary if its purpose is to secure a field of view. This report presents a case where UBE was useful to improve the effectiveness of spinal decompression in a narrow interlaminar space to treat residual neurological symptoms.