OBJECTIVE Residual ridges change in shape and reduce in size due to alveolar bone resorption. Therefore, the purpose was to investigate changes in denture base thickness (DBT) and interocclusal rest space (IRS) with regard to the denture relining procedure. METHODS The IRS and DBT were measured (before and after denture relining) in the case of 74 patients and their removable dental prostheses by using a precise sliding gauge. The DBT measuring was performed in 6 points for maxillary and in 3 points for mandibular removable dental prosthesis. The IRS values were measured as the distance (in mm) between the incisal edges of the maxillary and mandibular central incisors with patient's mandible in a physiological "rest position" with head and neck in the upright posture. RESULTS In a group of patients wearing maxillary and mandibular removable dental prosthesis mean values of DBT after denture relining were statistically significantly higher (p <0.05) in almost all measuring points. The IRS mean values after relining were statistically significantly lower (p <0.05). Statistically significant differences (p <0.05) of DBT were also observed in groups of "day-night time" and "day time" denture wearers, and in a group of patients for whom a period shorter than one year had passed since the last tooth extraction and the time when a functional impression for removable dental prostheses was taken. CONCLUSIONS The DBT and IRS values change after the denture relining procedure due to the alveolar bone resorption. Therefore, these measures could be used as resorption indicators in dental practice.