OBJECTIVE To compare rigid proctoscope and flexible endoscope for elastic band ligation of internal hemorrhoids. METHODS Patients between 18 and 80 years old, with chronic complaints (blood loss, pain, itching or prolapse) of internal hemorrhoids of grade 1-3, were randomized to elastic band ligation by rigid proctoscope or flexible endoscope (preloaded with 7 bands). Patients were re-treated every 6 wk until the cessation of complaints. Evaluation by three-dimensional anal endosonography was performed. RESULTS Forty-one patients were included (median age 52.0, range 27-79 years, 20 men). Nineteen patients were treated with a rigid proctoscope and twenty two with a flexible endoscope. Twenty-nine patients had grade 1 hemorrhoids, 9 patients had grade 2 hemorrhoids and 3 patients had grade 3 hemorrhoids. All patients needed a minimum of 1 treatment and a maximum of 3 treatments. A median of 4.0 bands was used in the rigid proctoscope group and a median of 6.0 bands was used in the flexible endoscope group (P < 0.05). Pain after ligation tended to be more frequent in patients treated with the flexible endoscope (first treatment: 3 vs 10 patients, P < 0.05). Three-dimensional endosonography showed no sphincter defects or alterations in submucosal thickness. CONCLUSIONS Both techniques are easy to perform, well tolerated and have a good and fast effect. It is easier to perform more ligations with the flexible endoscope. Additional advantages of the flexible scope are the maneuverability and photographic documentation. However, treatment with the flexible endoscope might be more painful and is more expensive.