Transcribing sign communication used simultaneously with spoken English presents investigators with a unique problem: the singular quality of the bimodal communicative interactions cannot be accurately depicted using accepted conventions for recording either spoken or signed language samples. This article proposes guidelines for transcribing such data. The need for guidelines arose during an earlier study of the language development of a hearing child of deaf parents. To meet the immediate needs of that study, rules and conventions from previous studies were combined with newly generated ones, resulting in the guidelines proposed in this article. The guidelines can be applied to data in which intermodal linguistic influence is suspected.