Purpose The aim of this 10-year follow-up study was to determine changes in health-related quality of life (HRQoL) over time among ambulatory persons with MS (PwMS) at the baseline using generic and disease-specific instruments. Methods Of 109 independently walking PwMS included in a population-based study in 2002, 77 (70.6 %) were re-assessed in 2012. HRQoL was captured using the 36-Item Short Form Survey Instrument (RAND-36), 15D instrument (15D), and the Multiple Sclerosis Quality of Life-54 (MSQOL-54). Repeated-measures ANOVA and effect size (ES) calculations (Cohen’s d) were used in the statistical analysis. Results The RAND-36 physical health composite score (p = 0.003, ES = 0.26) and 15D total score (p = 0.012, ES = 0.25) declined from the baseline levels. In particular, lower scores were observed on the RAND-36 scales of physical functioning (p = 0.001, ES = 0.27), pain (p = 0.020, ES = 0.25), and general health perceptions (p = 0.002, ES = 0.36), on the MSQOL-54 scales of physical functioning (p = 0.001, ES = 0.27), pain (p = 0.040, ES = 0.21), sexual functioning (p = 0.003, ES = 0.43), and satisfaction with sexual functioning (p = 0.012, ES = 0.38), and in the 15D dimensions of mobility (p = 0.004, ES = 0.31) and sexual functioning (p ≤ 0.001, ES = 0.59). Improvement was observed on the RAND-36 scale of social functioning (p = 0.049, ES = 0.25). The other composite scores, scales, and dimensions remained unchanged. Conclusion The results of this study suggest that ambulatory PwMS at baseline reported reduced HRQoL in physical functioning after a 10-year follow-up period, while emotional well-being was maintained and social functioning improved. The scores in the other HRQoL dimensions and scales remained unchanged. More long-term population-based studies are needed to precisely determine the development of HRQoL among PwMS.