Event-related potentials were used to investigate the interaction of verbal working memory and gender information during pronoun resolution. Gender information is supposed to be disentangled using sentences about persons (semantic/syntactic) or things (syntactic) followed by gender congruent or incongruent pronouns. Memory was manipulated using differential distances (short distance (SD) and long distances with or without intermediate subject gaps (LD gap and LD no gap)) between the pronoun and the antecedent. Comparing incongruent to congruent conditions, person sentences with SD and LD no gap resulted in an N400-like effect indicating the involvement of semantic integration, whereas a P600 effect in LD gap (re-activated antecedents) sentences suggested the involvement of syntactic reanalysis. SD-thing sentences showed a P600 effect, whereas LD thing sentences revealed no effect at pronoun position. A delayed N400 effect for thing sentences was observed instead. Based on preceding and the current data, we present a working model on how the parser switches between the use of semantic and syntactic information to establish co-reference and how this switch depends on the type of antecedent, distance, or syntactic structure.