The present study refers to a quantitative, morphometric analysis of exfoliative cytology smears collected from diabetes mellitus (DM) patients, in order to distinguish subtle changes in cellular and nuclear parameters. The study was carried out on 30 adult subjects: a control group of 10 healthy subjects and a study group of 20 diabetic subjects (type 1 and type 2 DM). Another factor that was taken into consideration was the abundance of the microbial flora. The oral smears were stained using Hematoxylin and Eosin and several parameters were measured (nuclear diameter, perimeter and area, cell large diameter and area), and calculated: nuclear/cytoplasmic ratio and nuclear roundness factor. We found out that the cells collected from DM patients had higher values of the nuclear parameters (the nuclei were larger) and lower cell dimensions. The nuclear to cytoplasmic ratio was increased in these patients, but the nuclear roundness factor was closer to one in the study group. Also, an increased number of bacteria, often seen in DM patients, decreased the nuclear parameters. Our findings complete recently descriptive cytology studies with the morphological measurements in case of bacterial abundance and sustain the possible value as screening method for morphometry.