Purpose: The aim of this study was to investigate the effects of upper extremity dynamic exercise on respiratory function and quality of life in children with Duchenne Muscular Dystrophy (DMD). Methods: In this study, children who diagnosed DMD scored as Level 1 or 2 according to the Brooke Upper Extremity Functional Classification (BUEFC) were divided into study and control groups with coin toss method randomly. Demographic datas were recorded. Timed performance tests (standing from supine, T-Shirt wearing/removing), electronic respiratory muscle strength device and Pediatric Quality of Life-3.0 (PedsQL-3.0) Neuromuscular Module child/parent questionnaire were used for evaluation of upper extremity performances, peak expiratory flow (PEF) and health-related quality of life, respectively. Study group had trained in arm ergometer, 8 weeks, 3 days per week, mean 40 minutes. Control group was applied normal range of motion upper extremity exercises as home programme. Assessments were repeated after 8 weeks. Results: 24 DMD children, 12 control and 12 study subjects, respectively with mean age 9.33±1.37 and 9.50±1.38 were evaluated. Statistically significant differences were found in favor of study group in standing from supine position and T-shirt wearing time after exercise program (p<0.05). Significant increase was found in PEF liter value in study group (p<0.01). There were positive, moderate correlation between PedsQL-child scores and PEF (r=0.590; p<0.05); negative, strong correlation between PEF and T-Shirt wearing time (r=-0.629; p<0.05). Discussion: It was found that upper extremity dynamic exercise with arm ergometer increased respiratory function and showed positive effect on quality of life of children with DMD.