Background/Aim: Few studies have specifically investigated treatment of prednisolone-induced hyperglycaemia. Aim: To determine if a basal bolus insulin (BBI) protocol for inpatient hyperglycaemia is effective in patients prescribed acute prednisolone for an inflammatory disease. Methods: In a cross-sectional study, 66 patients with type 2 diabetes admitted to a general medical ward and treated with BBI for up to 5 days were studied. Twenty-four patients were taking prednisolone ≥10mg/day to treat an acute inflammatory disease. The remaining 42 patients were a control group. The primary outcome was mean daily blood glucose level. Results: There were no significant differences in glycosylated haemoglobin (8.1 ± 1.0 vs 8.1 ± 1.6%, P = 0.88), age (77 ± 11 vs 75 ± 14 years, P = 0.57), male sex (63 vs 60%, P = 0.81) or body mass index (30.0 ± 5.3 vs 30.2 ± 11.5kg/m2, P = 0.90) between patients taking prednisolone and controls. Mean daily glucose concentration was higher in patients taking prednisolone than in controls (12.2 ± 0.3 vs 10.0 ± 0.1mmol/L, P < 0.001). Blood glucose level was higher in patients on prednisolone at 1700h (14.6 ± 0.6 vs 10.3 ± 0.3mmol/L, P < 0.001) and 2100h (14.5 ± 0.6 vs 10.5 ± 0.3mmol/L, P < 0.001), with no significant differences at 0700h and 1200h. These findings occurred despite patients taking prednisolone receiving a higher daily insulin dose than controls (0.67-0.70 vs 0.61-0.65U/kg, P = 0.001) because of higher doses of ultra-rapid-acting insulin at 1200h and 1700h. Conclusions: Hospitalised patients taking prednisolone had substantial afternoon and evening hyperglycaemia despite receiving BBI via a protocol for inpatient hyperglycaemia. Specific insulin regimens for prednisolone-induced hyperglycaemia are needed that recommend more insulin during this time period.