The authors report their experience of 30 patients with colorectal anastomotic stenosis treated by 62 dilatation sessions in order to evaluate which anastomotic characteristics could influence the success of dilatation therapy. Patients were subdivided into group A (dilatation successful) and group B (dilatation unsuccessful). Overall, dilatation was successful in 73.3% of cases, with only one important complication. The prognostic factors considered were anastomotic dehiscence, adjuvant radiotherapy, presence of colostomy at dilatation, site, morphology and length of the stenosis, presence of neoplastic recurrence, type of anastomosis and type of dilatation. Radiotherapy, local neoplastic recurrence and large anastomotic dehiscence were the more important independent prognostic factors. If present together, they were associated with an almost 100% probability of failure and, vice versa, if they were absent this probability was 5%.