Using event-related potentials, in this study we examined how implied emotion is derived from sentences. In the same sentential context, different emotionally neutral words rendered the whole sentence emotionally neutral and semantically congruent, emotionally negative and semantically congruent, or emotionally neutral and semantically incongruent. Relative to the words in the neutral-congruent condition, the words in the neutral-incongruent condition elicited a larger N400, indicating increased semantic processing, whereas the words in the negative-congruent condition elicited a long-lasting positivity between 300 and 1,000 ms, indicating an emotional response. The overlapping time windows of semantic processing and the emotional response suggest that the construction of emotional meaning operates concurrently with semantic unification. The results indicate that the implied emotional processing of sentences may be a result of unification operations but does not necessarily involve causal appraisal of a sentence's mental representation.