Scope of the study: A reliable, rapid and non-invasive evaluation of the patients suffering from diabetes mellitus through investigation of glycemia from the sulcular (crevicular) gingival blood. Materials and method: Laboratory investigations were made for evaluating the glycemia from the capillary (CBGL) and crevicular (SBGL) blood in 60 patients with periodontitis (30 suffering from diabetes, 30 non-diabetics), the obtained data being analyzed statistically. Results: The mean values of glycemia (at both MSBG-sulcular and MCBG-capillary level), expressed in mg/dl, were of 168.60 and, respectively, 190.57. The MCBG level was of 269.73 for the group with diabetes and of 111.40 for the non-diabetic ones, respectively, whereas the MSBG level was of 240.217 for the first group and of 97.03 for the second one. An important correlation could be also observed between the levels of these values and the degree of periodontal affection. Conclusions: Testing of sulcular blood may represent an adequate, rapid and reliable method for the identification of patients affected with diabetes, permitting to recommend a new screening protocol.