Differential cross sections for low-energy electron-impact excitation of the unresolved combinations of 2(3)B(2) + 2(1)A(1) and 3(1)A(1) + 2(1)B(2) electronic states of pyrimidine are reported. Comparisons are made with recent differential cross section measurements for the electron-impact excitation of the E-1(1u) and unresolved B-1(1u) + E-3(2g) electronic states of benzene [H. Kato, M. Hoshino, H. Tanaka, P. Limao-Vieira, O. Ingolfsson, L. Campbell, M. J. Brunger, J. Chem. Phys. 134 (2011) 134308.], in order to evaluate the nature of electron impact pi-pi* transitions in aromatic species. (C) 2012 Elsevier B.V. All rights reserved.