A prospective study was carried out to analyze the clinical and functional results of transsacral rectopexy with a DEXON^TM mesh in the elderly or poor risk patients with complete rectal prolapse. Six patients with complete rectal prolapse were operated from 1994 to 1996. All patients could be traced for examination with anorectal manometry and defecography. None of the patients had recurrence for the longest three years. In postoperative clinical symptoms, fecal incontinence score recovered from the preoperative mean score of 3.8 to the postoperative 1.2 and constipation was improved in 4 out of 5 cases (80.0%). Straining anorectal angle (S-ARA) by defecography improved from the preoperative value of 120.6±6.9° to the postoperative value of 98.5±3.5°(p<0.05) and the perineal descent (PD) improved from the preoperative value of 16.2±2.5 cm to the postoperative value 8.1±1.3 cm (p<0.05). Maximal resting pressure (MRP) increased from the preoperative value of 20.5±3.7 cmH₂O to the postoperative value of 40.5±4.8 cmH₂O (p<0.05). Transsacral rectopexy with DEXON^TM mesh for complete rectal prolapse is useful as this technique is simple to conduct, can be applied to the elderly or poor risk patients, replaces rectal prolapse, improves defecation troubles and recovers fecal incontinence.