Organ transplant patients suffer impaired immunologic defense mechanisms, including antimucosal defenses. The presence of prosthetic appliances within the oral cavity constitutes an additional factor promoting the development of infections. The aim of this study was to evaluate hygiene habits in relation to prosthetic appliances and one's own teeth practiced by patients after organ transplantation. The study was conducted for prophylaxis of stomatitis complicated by mucosal infection. The research group was composed of patients using prosthetic appliances and undergoing immunosuppressive therapy after kidney or liver transplantation. The control group included healthy wearers of prosthetic appliances. In the course of the initial interview, particular attention was devoted to hygienic habits in relation to the oral cavity and prosthetic appliances, the duration of their use, and the appearance of subjective symptoms. The following examinations concerned the oral mucosal membrane; mouth corners and hygienic condition of prosthetic appliances. Additionally, microbiological examinations were performed by taking a direct swab from the oral mucosa and the surface of dentures. The results of this study showed a greater frequency of prosthetic stomatitis complicated by mucosal infections among patients after organ transplantation, even though these patients exhibited better hygienic standards of the oral cavity and prosthetic appliances.