The role of fecal diversion alone for perianal Crohn's disease remains unclear. This study was undertaken to assess its role in perianal Crohn's disease and to examine predictive factors for outcome. Thirty-one patients who underwent fecal diversion alone for perianal Crohn's disease between 1970 and 1997 were reviewed. The principal indications for fecal diversion were severe perianal sepsis in 13 patients, recurrent deep anal ulcer in 3, complex anorectal fistula in 9, and rectovaginal fistula in 6. Twenty-five patients (81%) went into early remission, and six (19%) failed to respond. Of the 25 early responders, 17 relapsed at a median duration of 23 months after fecal diversion. By contrast, 8 patients (26%) went into complete remission and required no further surgery at a median duration of 81 months after the diversion. Altogether, 22 patients required surgery at a median duration of 20 months after fecal diversion: proctectomy in 21 and repeated drainage of anal sepsis in 1. At present, intestinal continuity has been restored in only three patients (10%). The following parameters were compared in patients with and without complete remission after fecal diversion: age, gender, duration of disease, steroid use, smoking, coexisting Crohn's disease, preoperative blood indices, and Crohn's disease activity index. None of these parameters affected the outcome. In conclusion, fecal diversion alone is effective in selected patients with perianal disease, but the prospect of restoring intestinal continuity is low. There were no parameters to identify those in whom a successful outcome is likely.