In this study, we questioned the role and the place of constructional morphology in bilingual dictionaries. As it is the case with monolingual dictionaries, it is becoming increasingly common to find morphological elements in bilingual dictionaries. Presenting such elements in a bilingual context, however, raises questions as to representations of meaning, translation selection and choice of examples. We show a comparison of the treatment of productive prefixes of Italian in 5 bilingual dictionaries-French was the target language in three of them, English in the other two. This comparison shows the differences in the treatment of prefixation and its coverage. First, we notice that not all the prefixes are represented in these dictionaries, and that some lexical elements are labelled as prefixes even if this status is contested. In terms of treatment, we examine in particular aspects of polysemy and of multiple translations. Regarding the polysemy of some prefixes, many dictionaries simply avoid marking the difference, while others add specific sense indicators. The most frequently used method for presenting the translation of prefixes, however, is through examples. In analysing these examples, we notice the inadequacy of certain translation equivalents, especially from a productive point of view. There is a noticeable absence of any information on the productivity of these constructional elements. From the perspective of understanding neologisms and sometimes even producing them, this lack of precision is regrettable.