Aims: Many people with diabetes do not achieve optimal blood glucose control which can contribute to unscheduled care (UC). This study sought to identify the factors that influenced people’s unplanned admission to hospital, to inform the development of interventions to reduce this form of UC. Methods: Twenty-eight participants with type 1 (18%) or type 2 (82%) diabetes were interviewed during or after discharge from two distinctly different localities and health services in the UK. The majority were male (61%) and aged >60 years (82%); average length of stay was 8.5 days (IQR 9.5). More than half (57%) were admitted for peripheral limb complications, others were for hyperglycaemia (18%), hypoglycaemia (10%), or for erratic blood glucose control alongside comorbidities (15%). Data were analysed using framework charting. Results: The progressive nature of participants’ ill-health was prominent in their accounts. Three key themes of ‘Knowledge’, ‘Provision’ and ‘Avoidance’ were identified as instrumental in UC. ‘Knowledge’ included participants’ understanding and experience of diabetes and that of non-specialist healthcare professionals as contributory factors. ‘Provision’ included poor access to and/or significant delays within community. ‘Avoidance’ included participants’ self-reported denial of and/or complacency to their illness severity and evasion of help-seeking. Summary: A focus on measures to prevent deterioration in prehospital glycaemic control is paramount to reducing UC in people with diabetes. This could be achieved through improved education for people with diabetes, ensuring acknowledgement of psychosocial interactions with health-behaviour. Improved training and skills acquisition for non-specialist services is also needed to reduce risk of UC.