Purpose: To quantify the depth of penetration of Candida albicans (C albicans) into a denture base resin and to investigate its viability after disinfection. Materials and Methods: Heatpolymerizing polymethyl methacrylate plates were contaminated with C albicans, then washed, dried, and prepared for scanning electron microscopy (SEM). Vertical surfaces were cut, and the depth of any penetration was measured. For viability after disinfection, plates were contaminated, subjected to one of two disinfection techniques, and subcultures were taken to determine viability. Results: The results showed that at 7, 14, and 21 days after exposure, the mean depth of penetration of C albicans was 33.9, 96.9, and 97.0 μm, respectively. The depth of penetration was time dependent, with the deepest being 631 μm at 21 days. Daily subcultures for 10 days revealed that penetrated cells remained viable and were not affected by the disinfectant. Conclusion: To the present authors' knowledge, this is the first time that the viability of denture base-penetrated C albicans has been shown, even after disinfection. The implication of these results is that denture resin is likely to be penetrated, especially in patients with chronic or recurrent denture stomatitis. If the C albicans remain viable, then the infected denture-fitting surfaces may have to be replaced by removing at least a 1-mm layer of contaminated resin.