Background: Due to extended indications and resynchronization therapy, many implantable cardioverter defibrillator (ICD) recipients will experience progressive co-morbid conditions and will be more likely to die of causes other than cardiac death. It is therefore important to elucidate the ICD patients' preferences when nearing end-of-life. Instead of avoiding the subject of end-of-life, a validated questionnaire may be helpful to explore patients' experiences and attitudes about end-of-life concerns and to assess knowledge of the function of the ICD in end-of-life. Validated instruments assessing patients' perspective concerning end-of-life issues are scarce. Aim: The purpose of this study was to develop and evaluate respondent satisfaction and measurement properties of the Experiences, Attitudes and Knowledge of End-of-Life Issues in Implantable Cardioverter Defibrillator Patients' Questionnaire' (EOL-ICDQ). Methods: The instrument was tested for validity, respondent satisfaction, and for homogeneity and stability in the Swedish language. An English version of the EOL-ICDQ was validated, but has not yet been pilot tested. Results: The final instrument contained three domains, which were clustered into 39 items measuring: experiences (10 items), attitudes (18 items), and knowledge (11 items) of end-of-life concerns in ICD patients. In addition, the questionnaire also contained items on socio-demographic background (six items) and ICD-specific background (eight items). The validity and reliability properties were considered sufficient. Conclusions: The EOL-ICDQ has the potential to be used in clinical practice and future research. Further studies are needed using this instrument in an Anglo-Saxon context with a sample of English-speaking ICD recipients.