We study the effects of the core size of an effective pseudopotential on the determination of the absorption spectra of Ag-n (n = 4-22) clusters. In particular, we debate over whether 4s and 4p semicore electrons should be treated as core or valence electrons in the framework of the time-dependent density functional theory. The present study shows that the use of small-core is suitable for the calculation of excited states for large clusters and to describe their electronic nature. (C) 2009 Elsevier B. V. All rights reserved.