Background: Diabetes is a common co-morbidity for patients with heart failure. Diabetes as a co-morbidity means that inpatient care should focus on both conditions to maximize the treatment regimen. However, this pressing issue is not widely researched and so it is unclear whether the acute care management needs of these patients are being met. Aims: (1) To assess the differences in the number of hospital readmissions between patients with heart failure and patients with heart failure–diabetes; (2) to assess the use of integrated care approach for patients with heart failure–diabetes during the index heart failure-related admission; (3) to explore patient experiences of admissions. Methods: A mixed methods design was used: we identified heart failure-related admissions between 1 April 2011 and 31 March 2012 in two hospitals, then reviewed medical records and interviewed 14 patients. Results: Over a 12 month period patients with heart failure–diabetes (n=172) had more heart failure-related Accident and Emergency attendance episodes (incident rate ratio 1.24, p<0.01) and hospital readmissions (incident rate ratio 1.23, p=0.01) than patients with heart failure (n=370). We reviewed 72 medical records which met inclusion criteria (adults with heart failure–diabetes, ejection fraction <45%): during admission most of them were reviewed by heart failure specialists but less than one-third were reviewed by diabetes specialists. The interview respondents addressed the need for better integration and co-ordination of care. Conclusions: This is one of the first UK studies to assess the integration of inpatient care for those with heart failure and multi-morbidities. The findings suggest that maximal care management during admission should be explored as a way of reducing the frequent readmissions and improving patient outcomes.