Introduction Basal/bolus insulin (BBI) is superior to sliding scale insulin (SSI) for diabetic patients admitted to hospital general medicine and surgery services, but little has been published on strategies to promote the utilization of BBI by resident physicians. New approaches that promote the effective management of hyperglycemia in hospitals need to be developed. Materials and methods A prospective study with historical controls was conducted to evaluate the impact of a pocket insulin dosing guide on the diabetes management practices of internal medicine resident physicians at the Southern Illinois University (SIU) School of Medicine, rotating on general medicine. The primary endpoint was the proportion of patients with preexisting diabetes mellitus managed with BBI. Pocket insulin dosing guides with instructions for initiating BBI and daily insulin adjustments were provided to all internal medicine residents in November 2010. BBI utilization rates were monitored over the period November 2010-February 2011 and were compared to the corresponding four-month period over the previous academic year (November 2009-February 2010), which was before the pocket insulin dosing guides were introduced (pilot study). Internal medicine house staff insulin ordering practices were subsequently evaluated for a 12-month period between October 2010-November 2011, with November 2009-October 2010 used as a historical control (study extension). New interns that were starting their residency training from July 2011 were provided with the pocket insulin dosing guides and given the same instructions as the previous academic year's resident physicians. Results Historical controls (N = 579) and study patients (N = 584) were well matched, with the exception of the male gender (49% vs. 41%, P = 0.01) and diet-managed diabetes (10.5% vs. 6.4%, P = 0.01). During the pilot study, BBI increased from 12.8% of all resident insulin orders in November 2010 to 58.1% of all orders in February 2011 (P < 0.01 for trend). Overall, BBI as a proportion of all resident insulin orders was 35.7% during the pilot phase, which is a six-fold increase over the previous academic year (6%), and was also statistically significant (P<0.01). For the 12-month period of evaluation between November 2010 and October 2011, internal medicine residents ordered BBI for 41.9% of diabetes patients, compared to 16.7% of patients in the 12 months before the pocket insulin dosing guide was introduced (P < 0.01). Patients managed with BBI had higher blood glucose values at admission than patients managed with SSI (195 ± 95 mg/dL vs. 178 ± 83 mg/dL, P < 0.01) and experienced a 41 mg/dL improvement in mean daily capillary blood glucose (CBG) as compared to no change for patients managed with SSI (P = 0.01 for trend). The rate of hypoglycemia, defined as CBG < 70 mg/dL, was 2.4% for both BBI and SSI managed patients (P = 0.93). Conclusion The SIU pocket insulin dosing guide significantly increased the utilization of BBI, decreased SSI orders, and improved hospital glycemic control for patients with diabetes mellitus. However, over half of the general medicine patients were still managed with SSI despite the pocket insulin dosing guides. Conversion of the insulin dosing guide to a smartphone app might improve utilization of the protocol and further increase the use of BBI for inpatient diabetes management by internal medicine house staff., Competing Interests: The authors have declared that no competing interests exist.