Heterogeneity in outcomes measured in trials limits accurate comparison of bronchiectasis studies. A core outcome set (COS) is an agreed, standardized set of outcomes that should be measured in trials for specific clinical areas. A COS for bronchiectasis could encourage consistency in future studies. An overview of systematic reviews and qualitative study on outcome selection in bronchiectasis informed an initial list of outcomes. A Delphi panel ( n = 86) rated the importance of each outcome from 1 to 9 in 3 sequential questionnaires, as a means to achieve consensus: 1-3 = 'of limited importance'; 4-6 = 'important, but not critical'; and 7-9 = 'critical'. Outcomes rated 'critical' by ≥70% of the panel were added to the COS. Eighty-two participants responded to the first questionnaire. Attrition between each questionnaire was 5%. After 3 rounds of questioning, 18 outcomes exceeded the threshold for consensus and were included in the COS. This study has achieved consensus on 18 outcomes that should be measured in trials of interventions for bronchiectasis. Selection of the highest ranked outcomes may represent a pragmatic means for comparison. Further research is required to condense the number of outcomes selected and to determine its relevance to interventions.