Introduction Our department conducted a retrospective cohort study to compare the efficacy of continuous glucose monitoring devices versus capillary blood glucose in the glycemic control of inpatient type 2 diabetes on intensive insulin therapy in a Portuguese hospital. The use of continuous glucose monitoring devices was associated with improved glycemic control, including an increased number of glucose readings within target range and reduced hyperglycemic events, being safe concerning hypoglycemias. This is the cost-effectiveness analysis associated with these results. Aim The primary objective was to compare the cost-effectiveness of achieving glycemic control, defined as the number of patients within glycemic goals, between groups. Secondary endpoints included cost-effectiveness analyses of each time in range goal, and each percentual increment in time in range. Methods We defined each glycemic goal as: "readings within range (70-180 mg/dL) >70%", "readings below range (below 70 mg/dL) <4%", "severe hypoglycemia (below 54 mg/dL) <1%", "readings above range (above 180 mg/dL) <25%", "very high glycemic readings (above 250 mg/dL) <5%". Results Continuous glucose monitoring showed lower median cost per effect for the primary outcome (€11.1 vs. €34.9/patient), with lower cost for readings in range (€7.8 vs. €11.6/patient) and for both readings above range goals ("above 180mg/dL": €7.4 vs. €9.9/patient, and "above 250mg/dL": €6.9 vs. €17.4/patient). Conclusions There are no published data regarding the cost-effectiveness of continuous glucose monitoring devices in inpatient settings. Our results show that continuous glucose monitoring devices were associated with an improved glycemic control, at a lower cost, and endorse the feasibility of incorporating these devices into hospital settings, presenting a favorable cost-effective option compared to capillary blood glucose.