In order to verify the influence of the adrenergic system on the gallbladder contraction the Authors studied the effect of isometeptene, a sympathomimetic drug active on beta receptors, on gallbladder emptying. The gallbladder was studied on 6 subjects using a real-time (linear array) equipment with a 3,5 MHz transducer. In fasting subjects the gallbladder emptying was obtained by a fatty meal. In the next day the fatty meal stimulation was associated with the administration of isometeptene. The mean values +/- S.D. of the follow parameters were evaluated: -gallbladder basal volume -gallbladder residual volume both after fatty meal and after the association with isometeptene -gallbladder maximum emptying percentage in two experiences. The results show that the isometeptene doesn't inhibit significantly the gallbladder emptying induced by a fatty meal.