To evaluate the efficacy, safety and complications of continuous glucose monitoring system (CGMS) in type 1 diabetic patients (DM1), we retrospectively studied 30 patients (25.8 +/- 12.2 years) submitted to 72 hs CGMS (Medtronic; Northridge, CA) and analyzed: mean self monitoring blood glucose (SMBG) and mean CGMS sensors glycemic value; correlation coefficient (%), median absolute percent difference (MAD%), number of sensor reading, glycemic excursions (CGMS vs. SMBG), complications (trauma, local infection, disconnection) and therapeutic management after CGMS. A1c levels were measured 1 month before and 3 months after the study. Mean capillary glucose values were 186.5 +/- 43.3 mg/dl vs. 179.7 +/- 48.1 mg/dl by CGMS sensor, with significant correlation (p = 0.001). An average of 772.4 +/- 254.1 (VR > 680) glucose measurements was recorded for each patient, with 68.7 +/- 19.8 hs of exam. Correlation coefficient was 0.86 +/- 0.21 (VR > 0.79). Median absolute percent difference between sensor and glucometer values was 13.9 +/- 4.7% (VR < 28%). The CGMS was significant more efficient in detection of glycemic excursion related to capillary glycemia (p = 0.009). This data showed important decreased level of A1c in this population 3 months after the CGMS with statistical significance (p = 0.018). No complications were registered in 96.7% of patients. No trauma, local infection or bleeding were registered. The insulin therapeutic regimen was adjusted in 100% of patients. The CGMS showed to be a very safety method, well tolerated, with high accuracy in glycemic values and low complications rate. This method has to be more stimulated by physicians and patients.