The aims of this study were to evaluate the effectiveness of six disinfection methods and the influence of these methods on the adaptation of maxillary dentures. Acrylic resin specimens contaminated with fungi were exposed to the following disinfection treatments: 1. microwave oven (900W) at full power for 5min (with soaking the specimen in 250ml water), 2. microwave oven at medium power for 5min (with soaking the specimen in 250ml water), 3. sodium hypochlorite 5.25% for 5min, 4. diluted sodium hypochlorite 1:420 for 5h, 5. Chlorhexidine gluconate for 5h, 6. effervescent tablets for 15min, 7. soaking in 250ml tap water for 15min. Colony forming units (CFUs) of remaining cells were counted and compared with t test (p≤0.05). Dimensional stability was evaluated using aluminum die simulating the maxillary edentulous arch. Posterior palatal gaps were measured. Data were analyzed using one-way ANOVA test and t test (p≤0.05). Microwave irradiation (at full or medium power) and sodium hypochlorite 5.25% for 5min were able to reduce the CFUs of fungi by more than 4 log10 whereas diluted sodium hypochlorite, chlorhexidine gluconate, and effervescent tablets did not achieve a reduction of >2.8, 2.68 and 1.66, respectively. For dimensional stability test, t test revealed significant difference between control group and the microwave at full power group (p=0.000). Within the limits of this study, microwave oven at medium power and sodium hypochlorite (5.25%) are effective and safe methods of disinfecting removable dentures.