BACKGROUND: We aimed to describe the health-related quality of life (HRQoL) in patients with neuromyelitis optica spectrum disorders (NMOSD), to compare HRQoL between NMOSD patients, multiple sclerosis (MS), and healthy controls (HC) and to study the associations between HRQoL and the clinical variables of the disease. METHODS: A cross-sectional study was carried out. Patients with NMOSD seropositive, MS, and HC were enrolled and age-matched. The HRQoL was studied using the Argentinean validation of the SF-36 health questionnaire. Demographic and clinical characteristics were analyzed, as well as the EDSS and the total scores and subscales of the SF-36. RESULTS: 243 individuals were included (NMOSD= 53, MS =100, and HC =90). The mean EDSS was 3.06 ± 2.01 in NMOSD and 2.67 ± 1.83 in MS with a mean of disease duration of 6.2 ± 4.4 and 6.3 ± 5.3 years, respectively. Significant statistical differences were observed in the total SF-36 score between both NMOSD and MS vs. HC (p < 0.01), but no differences were found when the total SF-36 score was compared between NMOSD vs. MS. Overall, NMOSD patients scored significantly lower in the total SF-36 and subscale scores compared to HC (p< 0.05). NMOSD patients also showed significant differences in bodily pain (58.8 ± 29.8 vs 75.1 ± 25.1, p < 0.01) and general health (44.4 ± 20.9 vs.31.9 ± 23.1, p < 0.01) when compared with MS, but no differences were found after comparing the rest of the subscales. We found that higher EDSS scores (ß -1.28 p = 0.03) and disease duration (ß 0.8, p = 0.02) were significantly associated to lower (worse) general health (dependent variable) score in NMOSD patients after having applied multiple linear regression analysis. Additionally, we observed that higher EDSS scores (ß -10.2 p = 0.008) and the presence of relapses in the previous year (ß -28.9, p = 0.02) were significantly associated to lower (worse) physical functioning (dependent variable) score. CONCLUSION: Pain seems to be a significant undertreated symptom in NMOSD patients that strongly impact on HRQoL. Patient-reported HRQoL scales scores provide comprehensive additional prognostic information beyond physical disability score.