We present an observation of extensive space-charge limited conduction in polybenzo[c]thiophene. Strong evidence for the presence of three discrete trapping levels is shown with a possibility of a fourth trap level. The density of traps for the first three levels is found to be 5×1016cm−3, 1×1017cm−3, and 2×1017cm−3, respectively. A lower limit for the free-carrier mobility was estimated to be ∼3×10−5cm2 V−1 s−1. ©1997 American Institute of Physics.