Negative priming (NP) refers to inefficient responding when previous distractors become targets. NP may reflect persisting inhibition of former distractors and/or retrieval of task-inappropriate information from the primes. In an event-related potential (ERP) study of the flanker task, NP was accompanied by reduced positivity in the P300 time range. The early portion of this effect was shared with a target-repetition condition and hence may indicate retrieval processes cued by repeated stimuli. A subsequent N400-like component was specific for NP and may reflect processing of the retrieved task-inappropriate information. In addition, NP effects on the lateralized readiness potential (LRP) matched predictions of the episodic-retrieval view. NP effects on P300, N400, and response-locked LRP were stronger in participants with above-median behavioral NP, confirming the significance of these ERP effects for NP. Overall, findings support episodic-retrieval explanations of NP.