In two experiments we investigated the relationship between the working memory skills of sign language interpreters and the quality of their interpretations. In Experiment 1, we found that scores on 3-back tasks with signs and words were not related to the quality of interpreted narratives. In Experiment 2, we found that memory span scores for words and signs under oral articulatory suppression were related to the quality of interpreted narratives. We argue that the insensitivity to articulatory suppression in memory span tasks reflects the interpreters' ability to bind information from multiple sources in episodic memory. This enhanced ability leads to less reliance on the retention of information from the source language in memory during interpreting, and will positively affect the quality of interpretations (Padilla, Bajo & Macizo, 2005). Finally, in contrast to previous studies on the memory spans for signs and words (Hall & Bavelier, 2010), we found that the memory spans scores for spoken words and signs were equally large. We argue that the use of a large set Pholoof phonologically complex stimuli in the present study may have stimulated participants to use a speech-based code to store and retain the signs in short-term memory.