The present study aimed to examine the efficacy of schema therapy on the severity of inflammation in RA patients. The research method was cohort entry and end of study. The research sample consisted of 30 RA patients meeting the study's inclusion criteria selected through purposeful sampling. The intervention method in this research was schema therapy based on Rizzo, Tweet, Stein, and Young's (2007) model. Descriptive statistics indicators were used to describe the research data, and inferential statistics indicators, including repeated measures analysis of variance, were used to analyze data. The results showed that 16 people (53.3%) were women and 14 (46.7%) were men, i.e., the ratio of males and females in the experimental and control groups was the same. The age range of the two research groups was between 27 and 61 years. The results showed that there is a significant difference (P ≤ 0.01) between the average scores of disease activity intensity and inflammation intensity in the stages before and after the intervention and follow-up, which means that the intensity of disease activity and inflammation intensity in the experimental group significantly You have decreased. On the other hand, the lack of post-test-follow-up difference in inflammation intensity scores (P > 0.05) showed that the effectiveness of schema therapy on the inflammation intensity of patients with RA was stable. It is suggested that in the country's health care system policy, plans should be made to use schema therapy to reduce the patient's pain.