We used time-dependent density-functional-theory (TDDFT) approaches to calculate absorption (S-0-->S-1) and emission (S-1-->S-0) transition energies of poly(p-phenylene vinylene) (PPV). The absorption and emission energies were estimated to be 2.44 and 2.16 eV, respectively, from the extrapolation of calculated results for oligomers. Comparisons with available experimental data demonstrated that TDDFT is a very reliable tool for investigating the electronic transitions of PPV. (C) 2004 American Institute of Physics.