ABSTRACTTechnetium labelled Sulphur Colloid (99mTc.S/C) is routinely used as the radiopharmaceutical in liver and spleen scanning. The radionuclide is taken up the Küpffer cells and macrophages of the reticuloendothelial system in the liver, spleen and bone marrow.Intraperitoneal injection of99mTc.S/C can be used to assess the patency of a peritoneo‐jugular (Le Veen) shunt in patients who develop recurrent ascites after insertion of the shunt. This technique has been previously described (Kirchmer, N.etal, 1977; Gorten, R. J., 1977; Rickers, L. F.et al, 1977; Williamsonet al, 1978). A further illustrative case is presented. Using a similar technique, we have been able to demonstrate a peritoneo‐pleural communication in a patient with recurrent pleural effusions and ascites. A similar situation has recently been described by Adamet al(1