A principle possibility is demonstrated to apply the ion track membranes as a template for the crystallization of inorganic salts. As an example, potassium iodide has been grown in a matrix of etched ion tracks produced in polycarbonate foils. Arrays of stable free-standing cylindrical microcolumns are observed after dissolution of the organic matrix. They represent single crystals oriented with their [100] or [110] crystallographic directions along the cylinder axes. Possible ways to govern their predominant orientations are briefly discussed. (C) 1998 Elsevier Science B.V. All rights reserved.