To evaluate initial periodontal treatment effects on gingival crevicular fluid (GCF) interleukin-6 (IL-6), tissue-type plasminogen activator (tPA), plasminogen activator inhibitor-2 (PAI-2), albumin levels in type 2 diabetic patients. GCF samples were collected from 20 type 2 diabetic, 22 non-diabetic non-smokers all with chronic periodontitis at baseline, 1-, 3-months following initial periodontal treatment. Biochemical analysis was performed by ELISA. Data were tested by Mann-Whitney U, Wilcoxon tests. The total amounts of albumin, IL-6, tPA, PAI-2 decreased significantly in diabetics after treatment (1- and 3-months) whereas, only PAI-2 decreased in non-diabetic group at 3-months (p < 0.05). There were statistically significant differences between the diabetics and non-diabetics at all time points for albumin, PAI-2 and at 1-, 3-months for GCF volume (p < 0.050) but only at baseline for IL-6 (p < 0.050). Present data suggest clinical improvements are less apparent in diabetic chronic periodontitis patients as reflected by disease markers in GCF and by an increase in concentrations of inflammatory proteins IL-6, tPA, and PAI-2 in GCF of this patient group following initial periodontal treatment.