The aim of this study was to evaluate the efficacy of biofeedback therapy in the treatment of dyssynergic defecation in chronically constipated community-dwelling elderly women.After an initial assessment phase carried out during 1 month, 20 chronically constipated women with dyssynergic defecation were randomly assigned to either electromyographic biofeedback (EMG-BF) group (n=10) or control group (n=10). Outcome measures used to evaluate the efficacy of treatment were weekly stool frequency, sensation of incomplete evacuation, difficulty evacuation level, mean EMG-activity (μV) of the external anal sphincter during straining to defecate and Anismus index.The results obtained in this randomized controlled trial showed significant differences between the groups in all the dependent variables after 1 month of treatment. Moreover, there was no difference between the groups neither in age nor in the duration of chronic constipation symptoms. At the follow-up, 3 months later, clinical gains were maintained.This study demonstrates that the EMG-BF is an effective behavioral therapy for the treatment of dyssynergic defecation in community-dwelling elderly women.