Patients suffering from rheumatoid arthritis (RA) are repeatedly affected by oral diseases or complaints, including xerostomia, periodontitis and dental caries. The aim of this systematic review was the evaluation of caries prevalence and/or incidence in patients with RA. Within this review, there is a systematic search of the literature based on PubMed, Web of Science and Scopus. Two independent researchers performed the search in February 2023. The search terms were “dental caries” AND “rheumatoid arthritis”. Additionally, a manual search completed the review process. Studies on adult patients (age ≥ 18 years) only suffering from RA were included. Studies had to explicitly report on the prevalence or incidence of dental caries. The respective studies were checked regarding suitability and, if they were eligible, analyzed qualitatively. A quality appraisal was performed for all of the analyzed studies. A total of 336 studies were detected, of which 16 studies met the in- and exclusion criteria. The sample sizes of the clinical investigations ranged between 13 and 1337 participants. Twelve studies evaluated a healthy control group. In 8/12 studies, a significant difference in the prevalence/incidence of caries was found between RA patients and controls. The majority of the studies applied the decayed (DT), missing and filled teeth index (DMFT) for the diagnosis of caries. On average (mean value), 0.8 to 5.79 carious teeth per patient were reported across the studies. There was no information on the stadium, activity or location of caries (e.g., root caries) in any study. Quality appraisal revealed a moderate quality for most studies. In conclusion, caries prevalence was heterogeneous across studies, while a higher caries prevalence was repeatedly reported in RA patients against controls. Further research regarding dental caries in RA appears recommendable; multidisciplinary, patient-centered dental care for patients with RA should be fostered to improve patients’ dental health status.