The thesis presents a study of explicitation and implicitation in translation. Explicitating and implicitating shifts were manually identified in a corpus of English and German business texts and their translations in both directions. Shifts were classified according to formal and functional critieria. The study departed from the observation that explicitations in one translation direction are often not 'counterbalanced' by implicitations in the other direction (cf. Klaudy's Asymmetry Hypothesis). The main aim of the study was to specify the conditions under which this state of 'explicitational asymmetry' can be observed. Unlike most other studies of explicitation in translation, the present study did not depart from the assumption of a 'translation-inherent', universal process of explicitation (cf. Blum-Kulka's Explicitation Hypothesis). Rather, the prediction underlying the study was that every instance of explicitation (and implicitation) can be explained as a result of lexicogrammatical and/or pragmatic factors. This prediction was essentially confirmed by the study's findings. Thorough qualitative analysis has made it possible to compile a list of factors that regularly lead translators to explicitate or implicitate. The factors explain why implicitations are often outnumbered by the corresponding explicitations.