The subject of the present work is the search for the semileptonic decay B- -> Lambda_c+ pbar l nubar. A measurement of this decay would allow us to quantize the underlying process and thus to improve our understanding of the mechanisms of baryonic B-meson decays in general. Predictions based on the measurement of other baryonic B-meson decays pointed to a branching fraction of the order 5*10^{-4}. These predictions could not be confirmed with the present work. Instead an upper limit of 1*10^{-4} for the branching fraction could be established.