The theoretical advantages of spondlylolisthesis reduction-fixation are substantial, but some questions such as excessive risk and morbidity relative to in situ fusion remain unresolved yet. This study included 10 consecutive patients(2 male, 8 female) who underwent posterior lumbar interbody fusion(PLIF) with transpedicular instrumentation(AKITA pedicular screw system) over the past six menths from July to December 1993. All patients were isthmic type, adult(between 30 and 57) and between grades I and II. Claudication was the most common symptom. All patients were operated upon by one surgeon(C.K.P.) and follow-up was conducted through patient interviews and examinations, both clinically and rediologically. The patients were followed postoperatively from 6 to 12 months. There were no neurologic complication related to the procedures. The clinical outcomes assessed more than 6 months postoperatively were as follows:improvement, 9/10;stationary 1/10. Radiologically, the mean reduction rate of slippage(preoperative percentage slip-postoperrative one/preoperative one x100) was 4.3% and all patients developed solid fusion. In conclusion, patients who underwent PLIF supplemented with transpedicular fixation had good overall clinical and radiological outcomes without significant neurological complications related to PLIF or screw placement.