This study evaluated the effect of an antimicrobial mouthrinse, denture soft relines, and a placebo rinse on the clinical findings and microbial flora of 78 patients with denture stomatitis. For 28 days the study and control groups performed oral rinses and denture soaks. Reline group patients had maxillary denture soft relines that were changed every 7 days. At the end of the study, the mean severity of denture stomatitis was significantly less in the groups that used the study rinse (P less than 0.01) and received denture relines (P less than 0.05) compared to the control. Analysis of variance revealed significant differences in ranked adjusted percentage counts in two out of 13 denture plaque organisms investigated (Fusobacterium nucleatum [P less than 0.05] and total Bacteroides [P less than 0.05]), with the antiseptic rinse producing the lowest count. Yeast populations were reduced, but not significantly (P = 0.07). In the absence of other mechanical denture hygiene procedures, the antiseptic rinse and relines were equally effective in reducing denture stomatitis and potential pathogens of denture plaque flora.