Computer-assisted spinal surgery is becoming more common; however, this is the first technical report to describe the technique of minimally invasive spinal posterior lumbar interbody fusion (MIS-PLIF) without using C-arm fluoroscopy. The authors report 2 years of follow-up of a 49-year-old female patient with L4 degenerative spondylolisthesis. The patient suffered from low back pain and intermittent claudication for more than 6 years. The authors performed computer-assisted MIS-PLIF without C-arm fluoroscopy. Instead, O-arm® navigation, the use of which reduces radiation exposure to patients as well as others in the operating room, was employed. Surgery was successful, and correct lumbar alignment was maintained. She had neither neurological deficits nor low back pain at her 12-month final follow-up. In conclusion, computer-assisted MIS-PLIF without C-arm fluoroscopy is a useful technique that reduces radiation exposure to the surgeon and operating room staff.