Purpose: To compare the frequency of denture stomatitis (DS) under maxillary complete dentures (CDs) in patients with opposing mandibular distal extension removable partial dentures (RPDs) and CDs. Materials and Methods: Participants included 365 maxillary CD wearers (241 women, mean age 70.5 +/- 13.2 years; 124 men, mean age 71.5 +/- 10.4 years) from 7 rest homes in Istanbul. A total of 268 had mandibular CDs; 97 had mandibular distal extension RPDs. Two independent, calibrated examiners performed oral examinations. Presence of maxillary denture-related stomatitis and the effect of risk factors on DS were evaluated and recorded. Results: The frequency of palatal DS (Newton I-III) was 45.1% (n = 121) in the mandibular CD group and 49.5% (n = 48) in the mandibular distal extension RPD group, a statistically insignificant difference (p= 0.4). Factors significantly associated with palatal DS were maxillary denture age (p= 0.02), reduced occlusal vertical dimension (p= 0.04), and nocturnal denture wear (p= 0.03). Conclusion: In this study, DS beneath maxillary CDs did not differ between mandibular distal extension RPD and CD wearers. The presence of mandibular anterior teeth did not influence the occurrence of palatal DS.