Pretreatment of denture acrylic with nystatin, amphotericin B and chlorhexidine gluconate significantly reduced the subsequent adherence of Candida species to acrylic, although chlorhexidine and nystatin were more effective than amphotericin B. The duration of chlorhexidine-mediated inhibition of adherence (up to 19 days) was much longer than that of amphotericin B (24 h) or nystatin (48 h). Exposure of stationary-phase cells of Candida species for a short period to sublethal concentrations of chlorhexidine, or growth of Candida species with sublethal concentrations of chlorhexidine for 24 h resulted in a reduction in the ability of the yeasts to adhere to denture acrylic. The organisms grown in the presence of chlorhexidine were more susceptible to spheroplasting with Zymolyase 20T, indicating that chlorhexidine affects the cell surface composition of Candida species.