Purpose: This study sought to investigate problems reported by patients before and after prosthodontic treatment. Materials and Methods: Patient-reported problems were studied using the item list contained in the German version of the Oral Health Impact Profile in a convenience sample of 107 prosthodontic patients before (T₀), 1 month after (T₁), and 6 to 12 months after treatment (T₂). "Frequently reported" problems were defined as impacts experienced fairly often or very often. The prevalence of frequently reported problems was compared among treatment groups and across appointments. Results: At baseline, the most prevalent frequently reported problems were "difficulty chewing" (31%), "take longer to complete a meal" (28%), "food catching" (26%), "uncomfortable to eat" (24%), and "unable to eat (because of dentures)" (23%). At T₂, the most prevalent frequently reported problems were "sore spots" (5%), "painful gums" (4%), "discomfort (because of dentures)" (3%), and "sore jaw" (2%). The number of reported problems decreased from 18.0 (T₀) to 7.5 (T₁), and further to 4.5 (T₂). The decrease was the fastest in fixed partial denture wearers and the slowest in removable partial denture wearers. Some problems emerged during or after prosthodontic treatment. The kind of pre- and posttreatment problems differed substantially. Conclusion: The number of problems decreased substantially after prosthodontic treatment. Fixed partial dentures more effectively influenced the problems reported before treatment than did removable partial or complete dentures.