The present study was conducted with the aim of comparing metacognitive beliefs and pain catastrophizing between women with fibromyalgia syndrome, women with chronic pain and normal women. In this research, 40 people with fibromyalgia syndrome, 40 people with chronic pain and 40 normal people were selected from the women of Tehran. The participants completed two scales, the short form of the Wells Metacognition Questionnaire and the standard pain catastrophizing questionnaire. The obtained data were analyzed using descriptive statistics, analysis of variance and post hoc tests in SPSS 26 software. The results of the one-way analysis of variance test show that the mean scores of the pain catastrophizing variable are higher in the fibromyalgia group than in the chronic pain group and are higher in the chronic pain group than in the normal group. The results of multivariate variance analysis of metacognitive beliefs show that, except for the variable of positive belief about worry, the average of metacognitive beliefs in fibromyalgia and chronic pain groups is higher than the normal group. According to the findings of this research, dealing with metacognitive beliefs and pain catastrophizing in the treatment of patients with fibromyalgia and chronic pain should be taken into account.