Static liquid holdup was determined in situ, in a column packed with Katapak-SP12 (TM) elements, using a non-intrusive X-ray tomographic technique. Experiments were performed in a 10 cm diameter PVC column with the air-water system. The technique allows a local determination of the various liquid holdup as well as of the capillary height, without dismantling the elements. Results are in good agreement with correlations proposed in the literature. (C) 2007 Elsevier Ltd. All rights reserved.