The word ἰδού is generally considered a mere colloquial interjection in the Classical period. Yet Euripides still makes use of its original injunctive meaning to focus the attention of internal and external audiences and draw it to important aspects of the dramatic action or visual performance. The article surveys a series of significant examples to show how ἰδού might trigger emotional and intellectual responses to specific gestures, moves or shifts in dramatic relations and invite the external audience to reflect on the art of theatre itself.