This study compared the effect of eye movement desensitization and reprocessing (EMDR) therapy versus guided imagery on insomnia severity in patients with rheumatoid arthritis (RA). In this randomized controlled trial, 75 patients with RA were selected via convenience sampling before using block randomization to assign patients into three groups comprised of (a) six sessions of EMDR, (b) six sessions of guided imagery, and (c) a control group. The Persian version of the Insomnia Severity Index was implemented at preintervention and 2 weeks’ postintervention as the outcome measure. The EMDR group obtained respective pre-and postintervention mean scores of 23.5 ± 5.2 and 11±2.1, whereas the guided imagery group obtained scores of 24 ± 3 and 15.3 ± 2.3, and the control group obtained scores of 24.2 ± 3.3 and 23.6 ± 3. Pairwise comparisons showed statistically significant differences in insomnia severity between patients from each group, with the EMDR group experiencing a greater reduction in insomnia severity than guided imagery. EMDR and guided imagery were both effective in reducing insomnia severity in RA patients, although the degree of insomnia reduction for patients from the EMDR group was greater than that of the guided imagery group.