Aims: Rheumatoid arthritis (RA) involves chronic pain that significantly impairs psychological well-being and daily functioning. This study aimed to investigate the efficacy of mindfulness training on reducing pain perception and enhancing self-efficacy in RA patients. Method and Materials: A quasi-experimental study utilizing a pre-test/post-test control group design was conducted in 2024. The population comprised RA patients who were referred to Shariati Hospital in Tehran. Eligible participants were assigned to experimental and control groups. The experimental group participated in eight 90-minute mindfulness training sessions, whereas the control group received routine care. Data were collected using the General Self-Efficacy Scale (GSE) and the McGill Pain Questionnaire (MPQ). The MPQ was utilized to assess four specific dimensions: sensory pain perception, affective pain perception, evaluative pain perception, and miscellaneous pain. The collected data were analyzed via Analysis of Covariance (ANCOVA). Findings: The mindfulness intervention significantly decreased all measured dimensions of pain perception (sensory, affective, evaluative, and miscellaneous) in the experimental group compared to the control group (P<0.001). Furthermore, the intervention led to a significant enhancement in the patients’ general self-efficacy scores (P<0.001). Conclusion: Mindfulness training serves as a highly effective complementary psychological intervention. By addressing cognitive responses to chronic illness, this structured program successfully mitigates multidimensional pain perception and fosters self-efficacy in patients with RA