Taking into account the dispersion and the longitudinal chromatic aberration (LCA) of the material of the lens. focusing of isodiffracting pulsed Gaussian light beam through single lens is analyzed. The smaller the cycle number of the isodiffracting, pulsed Gaussian light beam is, the higher the order of the material dispersion should be considered. (C) 2004 Elsevier B.V. All rights reserved.