Prostate-specific antigen (PSA) is an inflammatory marker produced by the epithelial cells of the prostate acini. In the presence of inflammation or malignancy of the prostate, PSA levels are > or = 4 ng/ml. This preliminary study was conducted to evaluate any association between periodontitis and PSA levels in chronic prostatitis patients. Thirty-five subjects who underwent prostate biopsy because of abnormal findings on digital rectal examination or elevated PSA (> or = 4 ng/ml) participated in the study. Plaque and gingival indices, bleeding on probing, probing depth, and clinical attachment level (CAL) were determined. Two-sided independent sample t tests assessed any significant differences in the PSA levels between and among the groups of prostatitis and periodontitis. Mean PSA levels were significantly higher (P = 0.04) in subjects with moderate/severe prostate inflammation than those with none/mild (8.8 +/- 5.8 versus 5.7 +/- 3.1 ng/ml). Subjects with CAL > or = 2.7 mm had higher but not statistically significant PSA levels than those with CAL <2.7 mm (7.7 +/- 5.2 versus 5.7 +/- 3.2 ng/ml), respectively. Individuals having both moderate/severe prostatitis and CAL > or = 2.7 mm (10.8 +/- 7 ng/ml) had significantly higher mean PSA levels (P = 0.05) than those with neither condition (5.6 +/- 3.7 ng/ml) nor only CAL > or = 2.7 mm (5.7 +/- 2.4 ng/ml) or moderate/severe prostatitis (6 +/- 1.9 ng/ml). Subjects having comorbidity of CAL > or = 2.7 mm and moderate/severe prostatitis have higher PSA levels than those with either condition alone.