To quantify and compare the insulin sensitizing property of aqueous extract of C. zeylanicum bark and rosiglitazone in dexamethasone induced insulin resistance. The animals were categorized into two series of dexamethasone (dexamethasone 4mg/kg, dexamethasone 8mg/kg series) with 5 groups in each [plain control, dexamethasone 4/8mg/kg as per series, rosiglitazone 8mg/kg and 16mg/kg, cinnamon bark extract (CZE) 250mg/kg BW]. In a12 day study period, rosiglitazone and CZE groups received respective drug treatments and dexamethasone dosing (4mg/kg or 8mg/kg) started from day 7onwards. On day 12, Fasting and post IPGTT blood samples were collected and processed for glucose and insulin estimations. In both series, CZE250mg/kg treatment showed significant reduction in mean fasting glucose and insulin compared to rosiglitazone8mg/kg, 16mg/kg groups and dexa controls (P<0.05).The CZE250/kg treatment improved HOMA-IR,HOMA-IS, FGIR and 30min post-IPGTT DI significantly compared to dexa controls and rosiglitazone groups(P<0.05)while, the 120min post-IPGTT DI among sensitizer groups was insignificant (P>0.05). Neither dexamethasone nor sensitizer treatment groups interfered with insulin secretion during IPGTT as the IGI sustained>0.4.Theperipheral glucose uptake (Gutt index) was significantly improved with rosiglitazone and CZE250mg/kg treatments over dexa controls (P<0.05) but, there was no significant difference between rosiglitazone and CZE250mg/kg groups (P>0.05). The whole body insulin sensitivity (Matsuda index) significantly improved with CZE250mg/kg compared to rosiglitazone and dexa control groups (P<0.05). The efficacy of CZE250mg/kg in steroid induced insulin resistance over rosiglitazone treatment as demonstrated by improved insulin sensitivity indices is substantiated.