This article discusses translation issues arising during the production of a British Sign Language (BSL) version of the psychological outcome measure "Clinical Outcomes in Routine Evaluation-Outcome Measure" (CORE-OM). The process included forward translation, meeting with a team of translators, producing a second draft of the BSL version and back translating into English. Further modifications were made to the BSL version before piloting it with d/Deaf populations. Details of the translation process are addressed, including (a) the implications of translating between modalities (written text to visual language); (b) clarity of frequency anchors: analog versus digital encoding; (c) pronouns and the direction of signing; and (iv) the influence of the on-screen format. The discussion of item-specific issues encountered when producing a BSL version of the CORE-OM includes the expression of precise emotional states in a language that uses visual modifiers, problems associated with iconic signs, and the influence of Deaf world knowledge when interpreting specific statements. Finally, it addresses the extent to which lessons learned through this translation process are generalizable to other signed languages and spoken language translations of standardized instruments. Despite the challenges, a BSL version of the CORE-OM has been produced and found to be reliable.