Denture stomatitis (DS) is often found under the removable partial dentures (RPDs). There are many factors influencing it, such as patient's age and gender, smoking habits, denture age, denture material, denture wearing habits, denture hygiene habits, oral hygiene instruction, denture cleanness and denture plaque accumulation. The aim of this study was to find out the influence these factors have on the prevalence of DS under RPDs and complete dentures (CDs). A total of 200 patients took part in this study. Half of the examined patients (100) wore CD and the other half (100) RPDs. There were 63 males and 137 females, aged between 45 and 83 years. Different smoking habits, denture wearing habits, denture hygiene habits, denture cleanness and oral hygiene instructions had significant influence on the degree of DS in CD wearers (p < 0.01). In the RPD wearers, denture material and denture support had a significant influence on DS (p < 0.01). The significant correlation was found between the denture plaque accumulation and the DS in complete maxillary and mandibular (rhoU = 0.85; rhoL = 0.61) and removable maxillary and mandibular partial dentures (rhoU = 0.45; rhoL = 0.62).