Background: Improvement of health-related quality of life (HRQOL) is a major goal in chronic disease management and HRQOL has become an important outcome in clinical trials. Longitudinal data on HRQOL are needed to elucidate change over time and to assess effectiveness of interventions; such research is lacking in the paediatric Duchenne Muscular Dystrophy (DMD) population. Methods: We followed up participants from our initial HRQOL study in 2013 a year and a half later. Multidimensional generic and disease-specific measures from the Pediatric Quality of Life Inventory were used to assess HRQOL from child and parent perspectives. Mean changes in HRQOL were calculated. Results: Data collection is ongoing and currently, data from 16 families (out of the initial 98) are available. Preliminary results indicated that by both child and parent reports, there were declines in all domains of HRQOL except for social function, in which there was a slight improvement. Mean decline in HRQOL scores ranged from 1.6 to 8.6 for child reports; and 3.3 to 7.7 for parent reports. Conclusion: HRQOL of boys with DMD deteriorates over time. Our results may be helpful in interpreting patient reported outcomes in forthcoming clinical trials and determining minimally clinically important changes in this population.