OBJECTIVES: There is currently no validated tool to evaluate nighttime symptoms in patients with COPD. The purpose of this study was to develop and test a patient reported outcome (PRO) self-administered questionnaire for evaluating COPD symptoms experienced during the night. METHODS: A review of the literature and interviews with six clinical experts informed the development of a framework for exploring patients’ experience with nighttime symptoms of COPD.  Four focus groups were conducted with twenty-seven subjects who experienced COPD symptoms at night or in the early morning.  Trained interviewers used a semi-structured interview guide, starting with open ended questions.  Grounded theory was applied using qualitative analysis software to identify key concepts and determine concept saturation.  A conceptual framework was developed to depict patients’ experience with COPD symptoms at night.  Items and response options were generated based on the qualitative data.  Subsequently, one-on-one cognitive debriefing interviews were conducted with 10 COPD patients to assess item readability, comprehensiveness, and content validity.  Items were edited based on feedback from the patients. RESULTS: Focus group participants had a mean age of 68.1 years; were 51.9% female; and had a range of COPD severity levels (GOLD Stages): 7.4% GOLD I (mild), 55.6% GOLD II (moderate), 14.8% GOLD III (severe), 22.2% GOLD IV (very severe).  A sizable majority (N=24; 88.8%) experienced COPD symptoms at night.  Focus group data supported saturation of concepts to evaluate how patients experience COPD symptoms at night.  Items were generated for the Nighttime Symptoms of COPD Instrument using patient terminology.  Subsequent cognitive debriefing with patients demonstrated that the items were understandable, relevant, and interpreted as intended. CONCLUSIONS: The Nighttime Symptoms of COPD Instrument is a PRO instrument developed to evaluate nighttime symptoms of COPD with documented evidence of content validity.  Psychometric testing is planned in order to evaluate the instrument’s measurement properties.