Here we present dielectric relaxation experiments carried out in semicrystalline poly (trimethylene terephthalate) (PTT) samples covering a broad range of crystallinity values. Special attention has been devoted to characterize the two extremes of low and high crystallinity. In particular a high temperature relaxation in the dielectric spectra of highly crystalline PTT, attributed to a Maxwell-Wagner-Sillars process, has been revealed. Moreover, the existence of ordering phenomena during the induction period prior to crystallization has been characterized by dielectric spectroscopy. (C) 2013 Elsevier Ltd. All rights reserved.