The aim of this study was to translate and culturally adapt the revised Piper Fatigue Scale to Swedish. For translation, guidelines for cross-cultural adaptation were used. Two teams independently translated the instrument and two other teams produced back-translations, after which a multidisciplinary committee decided on a Swedish version. In pre-test interviews, ten cancer patients were encouraged to think out loud while completing the Swedish version. Their verbal responses were analysed and used for a second revision. The initial translations varied in words, expressions and grammar, shown in a lack of equivalence to the original instrument after back-translation. In order to establish semantic equivalence, the committee changed some grammatical constructions, and some words were replaced for experiential and conceptual equivalence. When analysing the pre-test, obscurities due to the phrasing of some items were revealed and dealt with in the second revision. This study does not fulfil the process of validation for a translated instrument but offers a sound basis for further accumulation of evidence for validity, and facilitates the choice of an appropriate instrument for studying cancer-related fatigue in Sweden.