ObjectivesTo gain consensus on the items that determine adequacy of shift staffing.DesignThis was a three-round Delphi study to establish consensus on what defines adequacy of shift staffing in a general hospital ward. A literature review, focus group and five semistructured expert interviews were used to generate items for the Delphi study.SettingMulticentre study in The Netherlands.ParticipantsNurses, head nurses, nursing managers, and capacity consultants and managers working for Dutch hospitals.ResultsTwenty-six items were included in the Delphi study. One hundred and sixty-eight, 123 and 93 participants were included in the first, second and third round, respectively. After three rounds, six items were included (mostly related to direct patient care) and nine items were excluded. No consensus was reached on 12 items, including one item that was added after the first round.ConclusionsThis is the first study to specify items that determine adequacy of staffing. These items can be used to measure adequacy of staffing, which is crucial for enhancing nurse staffing methods. Further research is needed to refine the items of staffing adequacy and to further develop and psychometrically test an instrument for measuring staffing adequacy.