ABSTRACT : In semantics and pragmatics, presupposition is a key concept. However, we understand the role of presupposition considerably better in practice. Many linguists have pointed to the significant role of presuppositions in courtroom discourse. Crossexamining lawyers, in context of courtroom discourse, employ presuppositions with questions for implicitly assert evidence and the criminals are legally prohibited from denying. This research aims to investigate the function of presupposition in a qualitative manner based on the investigation of actual and authentic data from criminal cases. The work will demonstrate how Iraqi lawyers employ presuppositions in courtroom to entrap the criminals and confirm the evidences against them.