The mechanism of intramolecular electronic energy transfer (EET) in methylene-linked naphthalene and anthracene (referred to as AnN, n = 1, 3 and 6) was examined by time-correlated single-photon counting technique. The chain length dependance of measured EET rate constants is explained in terms of through-bond interaction via the connecting bridge, besides direct Coulombic interaction. In addition, intramolecular energy transfer in A1N and A3N may compete with vibrational relaxation of the corresponding vibrational level of the excited anthracene moiety by comparing the time-resolved spectra of A1N, A3N and A6N.