A patient with an excessively mobile accessory spleen detected on ultrasound examination is reported in whom a normally located spleen was also found. Sonographic and colour Doppler imaging criteria were used for making the specific diagnosis. The large accessory spleen has been demonstrated at different sites within the abdomen on subsequent follow-up sonographic examinations. The splanchnic flow pattern obtained from the long vascular pedicle of the accessory spleen indicated normal perfusion. Since the perfusion of the wandering accessory spleen was not compromised by torsion, and the patient refused surgical intervention, a conservative approach was considered to be appropriate.