Adjacent segment disease (ASD) is one of the potential risks after lumbar spine surgery with instrumentation. Revision surgery needs to be performed on patients suffered from ASD. The traditional open surgery takes severe injury to the body. We investigated the clinical outcome of using full-endoscopic transforaminal procedure to treat the single-level adjacent segment diseases after posterior lumbar fusion. 33 patients (average 71 years, ranged 65-84 years old) underwent full-endoscopic transforaminal procedure were involved. The Oswestry Disability Index (ODI), Modified Japanese Orthopedic Association (mJOA) score and visual analogue scale (VAS) score were used to evaluate the clinical effect. The complication, hospital stay, hospitalization costs and blood loss were investigated according to the patient’s records. The mean VAS score was 1.8 and mJOA score was 5.4 postoperatively. Improvement rate was 78%. The mean ODI was 14.6 postoperatively. The mean length of hospital stay, hospitalization costs and blood loss was 2.5 days, $3500 and 15 mL, respectively. No complication or recurrence was observed in any of the patients at the final follow-up. Full-endoscopic transforaminal procedure is a safe and effective technique. It is economical, acceptable and mini-invasive. Of course, it also can shorten the length of hospital stay and decrease bleeding. For revision surgery to treat ASD, this technique can achieve good clinical effects.