In this study, we compared health-related quality of life (HRQoL) scores of patients with rheumatoid arthritis (RA), fibromyalgia syndrome (FS), or ankylosing spondylitis (AS), with those of a selected sample of healthy individuals. The study group comprised 530 patients (264 with RA, 149 with FS, and 117 with AS). Three hundred fifteen healthy controls were used for comparison. HRQoL scores were obtained using the Short-Form (SF)-36 Health Survey. Frequency, mean, correlation, and multiple regression analyses were performed; in addition to the Student's t test, one-way ANOVA test, Kruskal-Wallis test, and chi-square test. The average physical component summary (PCS) and mental component summary (MCS) scores of patients in the RA, FS, and AS groups were much lower than those in the control group (p < 0.05). In all three patient groups, the lowest PCS score was found in the RA group, and the lowest MCS score was found in the FS group. The PCS scores of RA patients with disease-related changes in daily activities and the MCS scores of FS patients were lower (p < 0.05). In the three patient groups, the quality of life (QoL) of university graduates and those with a high level of income was good, whereas the QoL of patients who lacked information about the disease was poor. This study shows that AS, FS, and RA have a negative impact on HRQoL. Evaluating the HRQoL of patients with these conditions may provide guidance on their treatment and care.