It is well established that inpatients with diabetes are associated with poorer clinical outcomes. We therefore investigated the effects of introducing a point‐of‐care (POC) ward‐based glucose and ketones assessment to trigger a diabetes inpatient specialist nurse (DISN) proactive review to the ward, on the length of stay (LOS), 30‐day readmission rate and 30‐day mortality rate. Data were extracted for patients admitted to The Royal Derby Hospital during two six‐month periods in 2017 (pre‐intervention) and 2018 (post‐intervention). Data from four acute wards were used in the analysis, including two high dependency units (HDUs), an intensive care unit (ICU) and a medical admissions unit. The following clinical outcome measures were compared between the two groups: average LOS, 30‐day readmission rate and 30‐day mortality rate. Subgroup analysis was also performed to investigate the clinical outcomes for insulin‐treated patients. In total, 979 patient admissions were included in the study (n=443 in the 2017 pre‐intervention; n=536 in the 2018 post‐intervention). Thirty‐day readmission rates decreased significantly after the introduction of the POC‐DISN proactive review (29.3% to 20.1%, p=0.001). However, 30‐day mortality rates and the average LOS did not significantly decrease. Subgroup analysis showed that 30‐day readmission rates among the three wards (ICU and two HDUs) reduced further for patients using insulin (26.8% to 16.4%, p<0.05) compared to those not using insulin (26.6% to 22.2%, p<0.05). In conclusion, POC‐DISN intervention was effective in reducing 30‐day readmission rates for inpatients with diabetes. There was no significant impact on the 30‐day mortality rate or average LOS. Patients using insulin as part of their diabetes management were more likely to benefit from this intervention. Copyright © 2020 John Wiley & Sons.