Musculoskeletal disorders are the most common causes of deterioration in quality of life (QOL). We in this study aimed to assess (1) the impact of fibromyalgia syndrome (FS) on QOL comparing with that of rheumatoid arthritis (RA) patients and control subjects and (2) the impact of these two musculoskeletal disorders on various components of QOL using SF-36 Health Survey. Thirty-five patients with RA, 30 patients with FS, and 30 voluntary control subjects were included in the study. The groups were comparable in terms of demographic characteristics. QOL was evaluated by using Short-Form (SF)-36 Health Survey in all study participants, and Fibromyalgia Impact Questionnaire (FIQ), which is a specific health-status instrument for FS, was used in FS patients. Physical functioning, physical role, social functioning, bodily pain, general health, vitality, emotional role, and mental health scores were significantly lower in RA and FS patients than in control subjects (p<0.05). The between-groups comparisons revealed that FS patients had significantly lower mental health scores than RA patients (49.87 vs 62.51, respectively), (p<0.001). Total FIQ score correlated significantly with physical functioning, physical role, and bodily pain in FS patients. All parameters of SF-36 Health Survey except for social functioning correlated significantly with some of the variables of FIQ. FS has a negative impact on QOL, like RA. Furthermore, mental health was more severely affected in FS patients when compared with RA patients.