We study the exciton dynamics in ladder-type poly(p-phenylene) (LPPP) containing aggregate states under high electric field conditions. Time-resolved emission spectroscopy reveals a different dissociation behaviour of S-1-intrachain excitons as compared to excitons located in aggregate states. No acceleration of the decay of aggregate excitons due to field-induced dissociation is found for electric fields up to 2 x 10(6) V/cm. The time-integrated photoluminescence quenching does not exhibit a strong spectral dependence and is completely due to the dissociation of initially excited S-1-intrachain excitons. (C) 2002 Published by Elsevier Science B.V.