The present study was carried out to investigate and compare the thickness and number of rete pegs of the sulcular epithelium histometrically in bleeding and non-bleeding gingivae with special reference to comparisons of their relationship with corresponding stereomicroscopic findings. A total of 78 biopsies (40 bleeding and 38 non-bleeding gingival specimens) was obtained from 33 patients. Tissue sections with H&E stains were performed. Each gingival section was divided into three portions (coronal, middle and apical) along the gingival sulcular epithelium horizontally. The rete pegs were counted and the thickest and thinnest parts of the epithelium in three individual portions were also measured histometrically. The results show that the epithelial thickness of bleeding gingiva at the coronal and middle portions was significantly thinner than that of non-bleeding gingiva. There were also greater numbers of rete pegs of the sulcular epithelium in bleeding gingiva than of those in non-bleeding gingiva. However, there was no specific relationship between epithelial alterations of gingiva and the visibility of vasculature by stereomicroscopy. It is suggested that epithelial alterations of gingiva to some extent might be responsible for the gingival bleeding on probing clinically and highly associated with the volumetric density of underlying infiltrated connective tissue, but might not be related to the visibility of vasculature by stereomicroscopy.