In both healthy participants and various patient populations, performance on attentional set-shifting tasks has been found to be affected by learned irrelevance and/or perseveration. The present study examined whether or not these processes also play a role during the initial discrimination learning phase of those tasks. To this end, participants first solved a multidimensional discrimination learning task. Thereafter, they underwent three types of shift of relevant and/or irrelevant stimulus attributes, which enabled the assessment of the separate contribution of perseveration and learned irrelevance to post-shift task performance. Subsequent correlational analyses revealed that the number of errors during initial discrimination learning was significantly correlated with the number of errors in the learned irrelevance-shift but not the perseveration-shift. This suggests that processes underlying learned irrelevance in post-shift task performance also play a significant role during initial discrimination learning. The implications of these results for interpreting deficits in shifting are discussed. (Contains 1 table and 1 figure.)