Abstract Background This study aimed to achieve expert consensus regarding key items to be addressed by non-clinical operators using computer-software integrated medical dispatch protocols to manage out-of-hours telephone triage (OOH-TT) services for calls involving older adults seeking non-urgent unplanned care across Belgium. Methods A three-part classic e-Delphi study was conducted. A purposive sample of experts specialized in out-of-hours unplanned care and/or older persons across Belgium were recruited as panelists. Eligibility criteria included experts with at least 2 years of relevant experience. Level of consensus was defined to be reached when at least 70% of the panelists agreed or disagreed regarding the value of each item proposed within a survey for the top 10 most frequently used protocols for triaging older adults. Responses were analyzed over several rounds until expert consensus was found. Descriptive and thematic analyses were used to aggregate responses. Results N = 12 panelists agreed that several important missing protocol topics were not covered by the existing OOH-TT service. They also agreed about the nature of use (for the top 10 most frequently used protocols) but justified that some modifications should be made to keywords, interrogation questions, degree of urgency and/or flowcharts used for the algorithms to help operators gain better comprehensive understanding patient profiles, medical habits and history, level of support from informal caregivers, known comorbidities and frailty status. Furthermore, panelists also stressed the importance of considering feasibility in implementing protocols within the real-world setting and prioritizing the right type of training for operators which can facilitate the delivery of high-quality triage. Overall, consensus was found for nine of the top 10 most frequently used protocols for triaging older adults with no consensus found for the protocol on triaging patients unwell for no apparent reason. Conclusion Our findings show that overall, a ...