Berossos of Babylon wrote a piece of work in Greek, dedicated to Antiochos I (281-261 BC) about the history and the culture of his country. The only knowledge we have of his work, entitled Babyloniaca, is to be found in quotations, mainly those handed down by Josephus (Ist century AD) and Eusebios of Caesarea (4th century AD). Beyond the problem of the authenticity of the fragments attributed to Berossos, several questions are worth to be asked: Does Berossos give an accurate account of Mesopotamian traditions (notably in the Field of mythology)? If it is the case, isn’t it strange to Find ideas or motifs in his work that we don’t read anywhere else in cuneiform texts written in Akkadian or Sumerian? Or is it of particular interest for Berossos to praise Greek (or other non Mesopotamian) ideas, but then why is it of particular interest for him? Or do Ancient thinkers (and even later centuries thinkers) attribute their own ideas to Berossos, but why do they in this case? From the analysis of a few Babyloniaca fragments, we will try to suggest some answers to these questions.