The effect of fluid load on pain was estimated in 60 patients with acute ureteral colic treated with 50 mg. intravenous indomethacin. One group received 3 l. fluid intravenously, while in another group all fluids were withheld for 6 hours. Pain was assessed with a visual analogue scale. No intergroup difference in regard to pain was found after 1, 3 and 6 hours of observation.