In this study, we asked how the emotional status, i.e., valence and arousal, and concreteness of idioms contribute to their processing. Additionally, we asked whether the contribution of emotional factors and concreteness is modulated by other linguistic constraints, specifically idiom familiarity and decomposability, that has been shown to impact idiom processing. Participants read short idiomatic phrases (e.g., he kicked the bucket), word-by-word and for comprehension while their reaction time was recorded. The results showed that the emotional status of idioms contribute to their processing and this contribution is modulated by familiarity and decomposability levels of idioms in different ways. In particular, the impact of valence (i.e., the degree an idiom is pleasant/unpleasant) was modulated by familiarity, and the impact of arousal was modulated by decomposability. We did not find strong evidence for the contribution of concreteness for idiom processing. Our findings are aligned with theories of semantic representation, which suggest that besides linguistic information, sensory-motor and affective information are fundamental in representing meaning.