We present preliminary results of a study of defects in GaAs‐AlGaAs superlattices using deep‐level transient spectroscopy (DLTS). A dramatic difference is observed between the DLTS spectra of two superlattices when the superlattice period is doubled. This is explained by the presence of miniband conduction in the case of the smaller period and its absence in the case of the larger, and by the consequent difference in the distribution of electrons in the superlattice. Observed activation energies must be reinterpreted for comparisons to bulk material.