People with diabetes often have difficulty maintaining optimal blood-glucose levels, risking progressive complications that can lead to unscheduled care. Unscheduled care can include attending emergency departments, ambulance call outs, out-of-hours care and non-elective hospital admissions. A large proportion of non-elective hospital admissions involve people with diabetes, with significant health and economic burden. To identify precipitating factors influencing diabetes-related unscheduled hospital admissions, exploring potential preventative strategies to reduce admissions. Thirty-six people with type 1 (n=11) or type 2 (n=25) diabetes, admitted to hospital for unscheduled diabetes-related care across three hospitals in Scotland, Northern Ireland and the Republic of Ireland were interviewed. Participants were admitted for peripheral limb complications (n=17), hypoglycaemia (n=5), hyperglycaemia (n=6), or for comorbidities presenting with erratic blood glucose levels (n=8). Factors precipitating admissions were examined using Framework analysis. Three aspects of care influenced unscheduled admissions: inadequate knowledge; restricted provision; and complexities in engagement. Limited specialist professional knowledge of diabetes by staff in primary and community care, alongside inadequate patient self-management knowledge, led to inappropriate treatment and significant delays. This was compounded by restricted provision of care, characterised by poor access to services, in time and proximity, and poor continuity of care. Complexities in patient engagement, help-seeking, and illness-beliefs, further complicated the progression to unscheduled admissions. Dedicated investment in primary care is needed to enhance provision of and access to services, promoting increased and earlier diabetes specialist team involvement, alongside training and use of technology and telemedicine to enhance existing care.