The present paper focuses on the phenomenon of explicitation in simultaneous interpreting. In an attempt to provide an answer to one of the most contentious issues in the translation & interpreting studies community, this study aims at investigating the causes triggering shifts leading to greater explicitness of the target texts. The scope of the analysed explicitating shifts encompasses all linguistic strata, ranging from syntax and lexis to pragmatics. The analysis of both product and process data (retrospective comments) indicates that the vast majority of explicitating shifts in simultaneous interpreting are not attributable to the interpreters' conscious strategic behaviour.